COMMONWEALTH v. THOMAS MATTSON (2026)

MEMORANDUM AND ORDER PURSUANT TO RULE 23.0

After a jury trial, the defendant, Thomas P. Mattson, was convicted in the District Court of assault and battery on a person over sixty in violation of G. L. c. 265, § 13K (a 1/2). The defendant raises nine issues in this appeal. While the proceedings below were not entirely free of error, reversal is not warranted. Accordingly, we affirm.

Background. The defendant characterizes himself as a “First Amendment journalist.” He records interactions between government personnel and the public and publishes those recordings on his social media. On August 19, 2022, the Salem police and fire departments responded to a medical emergency near the Salem post office. The victim in this case, Walter Herbert, had called 911 after witnessing a young man fall and become unresponsive. Herbert remained at the scene after emergency services arrived.

The defendant heard a report of the emergency on his portable police scanner, went to the Salem post office, and began recording the incident both on his cell phone and with a camera he was wearing on his torso. Herbert, who was sixty-nine years old at the time, began speaking to the defendant, apparently telling him to stop filming the incident. The defendant and Herbert began arguing. Herbert then approached the defendant and stood face-to-face with him. The defendant pushed Herbert, causing Herbert to fall backwards onto the ground. Immediately after Herbert fell, the defendant shouted, “Don't spit in my face ever, you motherfucker.” An emergency responder then intervened. The defendant recorded the entire incident.

On August 23, 2022, the defendant was arraigned on charges of assault and battery with a dangerous weapon on a person over sixty in violation of G. L. c. 265, § 15A (a); assault and battery on a person over sixty with injury in violation of G. L. c. 265, § 13K (b); and wanton destruction of property worth over $1,200 in violation of G. L. c. 266, § 127.

The trial court docket reflects that five hearings marked “C/E” were continued between November 17, 2022, and March 9, 2023. A compliance and election hearing was eventually held on May 9, 2023. Amidst the continuances, on January 9, 2023, the defendant filed a motion to dismiss for lack of probable cause. A judge (first motion judge) denied the motion.

On September 26, 2023, the defendant filed a motion to dismiss pursuant to Mass. R. Crim. P. 36, 378 Mass. 909 (1979), alleging he had not received a speedy trial in accordance with the rule. A different judge (second motion judge) denied the motion, finding that “there were at least 212 days of excludable time pursuant to Rule 36 (b) (2)” that could not be charged to the Commonwealth. The trial court docket reflects that a third motion to dismiss was withdrawn by the defendant's counsel on June 18, 2024.

The defendant's trial began on October 28, 2024. Shortly before jury empanelment, the Commonwealth dismissed count 1, count 3, and the “with injury” element of count 2, leaving only a single count of assault and battery on a person over sixty in violation of G. L. c. 265, § 13K (a 1/2) to be tried. During trial, the parties stipulated that the jury would be informed of criminal charges then pending against Herbert. The trial judge instructed the jury that it was to consider that evidence “for the purpose of determining who attacked whom first,” but “not ․ for any other purpose.” On October 29, 2024, the jury found the defendant guilty. The defendant timely appealed.

Discussion. The defendant presents nine claims on appeal. We address each issue in turn.

1. Dismissal of charges. The defendant first argues that the trial judge abused his discretion under Mass. R. Crim. P. 4 (d), 378 Mass. 849 (1979), by allowing the Commonwealth to amend the charge of assault and battery on a person over sixty with injury shortly before jury empanelment. We note from the outset that, although the parties’ briefs address the issue as one of amendment, it is properly viewed as one of dismissal. The trial prosecutor moved to dismiss, not amend, the element of injury in count 2.

“In the context of criminal prosecutions, the executive power affords prosecutors wide discretion in deciding whether to prosecute a particular defendant, and that discretion is exclusive to them.” Commonwealth v. Cheney, 440 Mass. 568, 574 (2003). “Judicial review of decisions which are within the executive discretion of the [prosecutor] would constitute an intolerable interference by the judiciary in the executive department of the government and would be in violation of art. 30 of the Declaration of Rights” (citation omitted). Commonwealth v. Kardas, 93 Mass. App. Ct. 620, 624 (2018).

The trial prosecutor's dismissal of charges before empanelment was an exercise of executive branch discretion insulated from our review. See Kardas, 93 Mass. App. Ct. at 624-625; see also Mass. R. Crim. P. 16 (a), as amended, 489 Mass. 1501 (2022). Accordingly, the trial judge did not err by granting the Commonwealth's motion to dismiss the element of injury in count 2.

2. Limitation of cross-examination. The defendant contends that the judge's limitation of the scope of cross-examination violated his rights under both article 12 of the Massachusetts Declaration of Rights and the Sixth Amendment to the United States Constitution. Since the error alleged is one of constitutional dimension, we “must determine, first, whether the defendant's constitutional rights were violated, and, second, if a violation is found, whether reversal is warranted because the error was not harmless beyond a reasonable doubt.” Commonwealth v. Vardinski, 438 Mass. 444, 450 (2003). It is the Commonwealth's burden to show harmlessness. Commonwealth v. Tyree, 455 Mass. 676, 701 (2010).

The trial judge erred in barring any cross-examination regarding Herbert's pending criminal charges to show bias. The defendant was “entitled as [a] right” to cross-examine Herbert “in order to show [his] motive in cooperating with the prosecution” (citation omitted). Commonwealth v. Carmona, 428 Mass. 268, 270 (1998).

Nevertheless, the error was harmless beyond a reasonable doubt. The Commonwealth presented a video recording of the incident, from the defendant's perspective, that materially corroborated Herbert's testimony. More importantly, the video recording rendered Herbert's credibility immaterial to the verdict. Accepting that an unrestricted cross-examination would have established that Herbert's pending criminal charges provided him with a motive to curry favor with the Commonwealth and damaged his credibility, the jury would have reached the same verdict based on the video recording alone. The erroneous limitation of cross-examination therefore was harmless beyond a reasonable doubt. See Commonwealth v. Ramsey, 466 Mass. 489, 494 (2013) (“An error may be considered harmless when other properly admitted evidence of guilt is so overwhelming as to nullify any effect that the ․ evidence might have had on the outcome” [quotation and citation omitted]).

3. Withholding exculpatory evidence. The defendant next argues that the Commonwealth failed to disclose exculpatory medical records in violation of Brady v. Maryland, 373 U.S. 83, 87 (1963). To establish a Brady violation, the defendant “must show that (1) material information was in the possession of the prosecutor ․ (2) the information tended to exculpate [the defendant]; and (3) the prosecutor failed to disclose the evidence.” Commonwealth v. Caillot, 454 Mass. 245, 261-262 (2009).

As an initial matter, we agree with the Commonwealth that portions of the defendant's record appendix on which he relied in support of his Brady claim are not properly part of the appellate record because they contain material that was never presented to the trial court. “The right of parties to have an appellate court consider a paper is circumscribed ․ by whether it was introduced into the record of proceedings before the trial judge.” S. Kemble Fischer Realty Trust v. Board of Appeals of Concord, 9 Mass. App. Ct. 477, 480 (1980). Because we find no indication that page 100 and pages 106 to 116 of the defendant's record appendix were part of the trial record, the Commonwealth's motion to strike is allowed as to those pages.¹

Turning to the merits, the defendant's Brady claim fails because “the [Commonwealth's] obligation to disclose alleged exculpatory evidence extends only to those things in [its] possession or subject to [its] control.” Commonwealth v. Healy, 438 Mass. 672, 679 n.8 (2003). The defendant sought Herbert's medical records from the day of the incident. The Commonwealth's certificate of discovery compliance reads, in pertinent part, “the Commonwealth has been alerted that both sets of medical records ․ were deposited with the Clerk in December 2022 and are available to both parties to inspect and copy at their convenience.” In other words, the Commonwealth neither possessed nor controlled the evidence at issue. Instead, the court possessed the evidence and properly made it available to both parties. That fact alone is dispositive of the defendant's claim. See id.

4. Speedy trial. Next, the defendant asserts that the motion judge erroneously denied his motion to dismiss under Mass. R. Crim. P. 36 (b) (1) (C), and that the delayed proceedings violated his right to a speedy trial under article 11 of the Massachusetts Declaration of Rights and the Sixth Amendment to the United States Constitution. Each claim requires a distinct analysis. Commonwealth v. Dirico, 480 Mass. 491, 493 (2018).

a. Rule 36 claim. Mass. R. Crim. P. 36 (b) (1) (C) provides that “a defendant shall be tried within twelve months after the return day in the court in which the case is awaiting trial.” Under rule 36, “a criminal defendant who is not brought to trial within one year of the date of arraignment is presumptively entitled to dismissal of the charges unless the Commonwealth justifies the delay.” Commonwealth v. Spaulding, 411 Mass. 503, 504 (1992).

On September 26, 2023, the defendant filed a motion to dismiss under rule 36, citing delay caused by numerous continuances. “The speedy trial clock tolls at the time the defendant filed his motion to dismiss for lack of a speedy trial.” Dirico, 480 Mass. at 506 n.11. The defendant was arraigned on August 23, 2022. Thus, the defendant established a prima facie violation of rule 36 because 399 days elapsed between arraignment and the filing of his motion to dismiss. The burden therefore shifted to the Commonwealth to justify the delay. See Spaulding, 411 Mass. at 504. Subtracting twelve months (i.e., 365 days) from this period leaves thirty-four days that the Commonwealth had the burden to show were excludable.²

The Commonwealth can meet its burden of justifying a delay by demonstrating that the defendant acquiesced in the delay. “Under the common law, a defendant is not entitled to dismissal if he or she acquiesced in, was responsible for, or benefited from the delay.” Dirico, 480 Mass. at 498-499. A defendant is held to have acquiesced in a delay if he or she “agreed to a continuance ․ or has not entered an objection to delay.” Barry v. Commonwealth, 390 Mass. 285, 298 (1983). Thus, in several cases, the Supreme Judicial Court has excluded time under rule 36 based on the defendant's failure to object to a delay. See, e.g., Commonwealth v. Roman, 470 Mass. 85, 93 (2014) (time excluded where defendant failed to object to continuance); Commonwealth v. Denehy, 466 Mass. 723, 731-732 (2014) (same); Commonwealth v. Lauria, 411 Mass. 63, 68-69 (1991) (same). In doing so, the Supreme Judicial Court has “emphasized that rule 36 imposes obligations on all parties, and that it is the obligation of criminal defendants to ‘press their case through the criminal justice system.’ ” Dirico, supra at 499, quoting Lauria, supra at 68. Thus, defendants are required to object to delays in order to preserve their rights under rule 36 because “otherwise, ‘the public interest ․ [may] be thwarted by those defense counsel who decide that delay is the best defense tactic.’ ” Dirico, supra, quoting Barry, supra at 297.

The trial court docket indicates that five court hearings were continued between November 17, 2022, and March 9, 2023. The parties did not present any contemporaneous records indicating whether the defendant objected to any of these continuances. Then, on March 9, 2023, the case was continued until May 9, 2023. Again, the parties did not present any contemporaneous records indicating whether the defendant objected to this continuance.

In response to the defendant's motion to dismiss, the Commonwealth created a chart listing each of the court hearings prior to September 26, 2023. According to the Commonwealth's calculation, 212 days were excludable from the rule 36 calculation. More specifically, in the chart the Commonwealth asserted that on March 9, 2023, “Defense counsel request[ed] [a] further date and also [reported that he was] still considering whether he [would] file an appearance.” On November 14, 2023, the motion judge held a hearing on the defendant's motion to dismiss. The Commonwealth introduced the chart as an exhibit at the hearing. The second motion judge denied the defendant's motion to dismiss, finding that “at the time of the hearing on the motion, there were at least 212 days of excludable time pursuant to rule 36 (b) (2).”³ We infer from this record that the judge credited the Commonwealth's exhibit, including the representation that on March 9, 2023, at a compliance and election hearing an attorney appeared, explained that he was still considering whether to represent the defendant, and requested a continuance until May 9, 2023. Therefore, the judge found that the sixty-one days between March 9, 2023, and May 9, 2023, were excludable because the defendant “was responsible for, [and] benefited from the delay.” Dirico, 480 Mass. at 499. In sum, the judge found that the Commonwealth satisfied its burden to demonstrate that there were fewer than 365 days of nonexcludable time between the defendant's arraignment and the date he filed his motion to dismiss. Because there is nothing in the record before us to contradict this finding, we conclude that the judge did not err.⁴

b. Constitutional claim. The defendant also argues, for the first time on appeal, that the delay violated his constitutional rights. “Although a defendant who fails to prove a rule 36 (b) violation faces an uphill battle in proving a violation of his ․ constitutional rights to a speedy trial, the analysis is somewhat different.” Dirico, 480 Mass. at 505. “[T]o trigger a speedy trial analysis, an accused must allege that the interval between accusation and trial has crossed the threshold dividing ordinary from presumptively prejudicial delay” (quotation and citation omitted). Id. “Where a defendant has established presumptive prejudice, we apply the four-factor test articulated in Barker v. Wingo, 407 U.S. 514, 530-531 (1972), to evaluate whether the defendant's constitutional right to a speedy trial has been violated” (quotation and citation omitted). Id. at 506. “Under the Barker test, a reviewing court weighs the length of the delay, the reason for the delay, the defendant's assertion of his right to a speedy trial, and prejudice to the defendant.” Id., citing Barker, 407 U.S. at 530. No single factor is dispositive. See Commonwealth v. Larace, 496 Mass. 664, 667 (2025). Finally, even if a constitutional violation occurred, reversal is warranted only where the violation created a substantial risk of a miscarriage of justice. See Commonwealth v. Randolph, 438 Mass. 290, 294-295 (2002).

The Commonwealth concedes that the 797-day period between the issuance of the complaint and the date of trial amounts to presumptively prejudicial delay. Nevertheless, the remaining Barker factors establish that no constitutional violation occurred.

First, as discussed supra, the record is insufficient to establish the cause of the delay. Second, while the defendant was not required to “storm the [c]ourthouse and batter down the doors to preserve his right to a speedy trial,” we agree with the Commonwealth that the defendant's single motion to dismiss under rule 36, filed more than one year before trial and never renewed, was at best a “soft assertion” of his constitutional rights. Commonwealth v. Butler, 464 Mass. 706, 716 (2013). Our cases require more. See Commonwealth v. Beckett, 373 Mass. 329, 333 (1977) (holding defendant's assertion of his right to speedy trial weighed against defendant because he “did not object at any time to the numerous continuances which were granted” and made single motion to dismiss that was never renewed). Contrast Larace, 496 Mass. at 672 (holding defendant's assertion of his right to speedy trial weighed in his favor where he “repeatedly objected to the Commonwealth's requests for continuances and ultimately filed a motion to dismiss and later a renewed motion to dismiss under rule 36”).

Finally, the defendant has not made an adequate showing of prejudice. He states, without further argument, that the delay resulted in “extended restrictive bail conditions, prolonged anxiety, reputational harm, and diminished ability to prepare due to late discovery.” These undeveloped assertions do not suffice to demonstrate prejudice, particularly in the absence of any record support. See Commonwealth v. Grace, 370 Mass. 746, 758 (1976) (“The defendant's mere assertion of a legal conclusion, without citation of supporting authority or any real amplification of the issue, is the type of assertion ․ which we have consistently held insufficient to comply with our rules”). In light of all the circumstances, we conclude that the defendant was not denied his constitutional right to a speedy trial. Consequently, the delay did not create a substantial risk of a miscarriage of justice, and reversal is not appropriate. See Randolph, 438 Mass. at 294-295.

5. Probable cause. The defendant claims that the first motion judge erred in denying his motion to dismiss for lack of probable cause. “A motion to dismiss a complaint is decided from the four corners of the complaint application, without evidentiary hearing” (quotation and citation omitted). Commonwealth v. Humberto H., 466 Mass. 562, 565 (2013). “To establish probable cause, the complaint application must set forth reasonably trustworthy information sufficient to warrant a reasonable or prudent person in believing that the defendant has committed the offense” (quotation and citation omitted). Id. Probable cause must exist as to each essential element of the offenses charged. Id. at 565-566. We review the trial judge's probable cause determination de novo. Id. at 566.

The complaint was sufficient to establish probable cause that the defendant committed assault and battery on a person over sixty with injury. It states that the defendant pushed Herbert, then sixty-nine years old, and that Herbert “was being checked for neck and back pain.” The complaint further states that Herbert was transported via ambulance to a nearby hospital. On its face, the complaint sets forth sufficient information to establish probable cause as to each element of the offense, including injury. Therefore, the motion to dismiss was properly denied.⁵

6. Retaliatory prosecution. The defendant asserts that his conviction is the product of retaliatory prosecution. More specifically, he claims that the prosecution was undertaken to “punish” his “First Amendment journalism.” Not only is this claim raised for the first time on appeal, with an insufficient record to support it, it plainly lacks merit. To establish a claim of retaliatory prosecution, defendants must demonstrate that there was a lack of probable cause to pursue the charges against them. See Hartman v. Moore, 547 U.S. 250, 252 (2006). The defendant cannot do so for the reasons discussed in section 5, supra. Accordingly, his retaliatory prosecution claim must fail.

7. Selective enforcement. The defendant also challenges his prosecution as selective enforcement. Although this claim too is unpreserved and without record support, we address it briefly. Had the defendant properly filed a motion to dismiss to raise this issue, a two-step analysis would have applied. See Cote-Whitacre v. Department of Pub. Health, 446 Mass. 350, 376 (2006) (Spina, J., concurring). First, the judge would determine whether “the person, compared with others similarly situated, was selectively treated” (quotation and citation omitted). Id. (Spina, J., concurring). Second, the judge would ask whether “such selective treatment was based on ․ intent to inhibit or punish the exercise of constitutional rights, or malicious or bad faith intent to injure a person” (quotation and citation omitted). Id. (Spina, J., concurring).

The defendant seems to argue that Herbert was similarly situated to him vis-à-vis the underlying altercation because, in the defendant's view, Herbert's role in the conflict also merited criminal prosecution. To the extent this argument rests on the defendant's allegation that Herbert spat in the defendant's face, it is without merit. There is no evidence in the defendant's video recording to support this claim. The video recording illustrates only that Herbert argued with the defendant, and the defendant responded by pushing him to the ground. In any event, Herbert, the victim, was not “similarly situated” to the defendant in any material respect. Cote-Whitacre, 446 Mass. at 376 (Spina, J., concurring). The defendant's selective enforcement claim therefore fails.⁶

8. Ineffective assistance. The defendant next argues that his trial counsel was constitutionally ineffective. When reviewing ineffective assistance claims, we first ask whether trial counsel's performance fell “measurably below that which might be expected from an ordinary fallible lawyer.” Commonwealth v. Saferian, 366 Mass. 89, 96 (1974). If counsel's performance was deficient, we then determine whether the deficiency “likely deprived the defendant of an otherwise available, substantial ground of defence.” Id.

“The preferred method for raising a claim of ineffective assistance of counsel is through a motion for a new trial.” Commonwealth v. Zinser, 446 Mass. 807, 810 (2006). “An exception to that rule is that a claim of ineffective assistance may be resolved on direct appeal of the defendant's conviction when the factual basis of the claim appears indisputably on the trial record” (quotation and citation omitted). Id. at 811.

Because the defendant did not file a motion for a new trial, our review of his ineffective assistance claim is limited to claims supported by “indisputable” evidence of deficient performance in the trial record. See Zinser, 446 Mass. at 811. There is no such evidence in the record. Indeed, nearly all of trial counsel's purported shortcomings, such as his “refusal to file a motion challenging the unconstitutional stay-away/no-contact restriction” or “withdrawing his motion to dismiss without due diligence,” constitute conclusory allegations raising obvious questions of tactics and strategy, and thus are not suitable for appellate review. See Grace, 370 Mass. at 758. The defendant's remaining allegations, such as counsel's failure to object to the pre-empanelment dismissal of charges, are largely duplicative of other issues addressed above. In short, because the record does not present any indisputable evidence of defense counsel's deficient performance, we must reject the defendant's ineffective assistance claim.

9. Cumulative error. Finally, the defendant argues that the cumulative effect of “all constitutional, procedural, and institutional violations” in this case merits reversal. Because the only error in the trial court proceedings was harmless beyond a reasonable doubt, its cumulative effect was likewise harmless.

Judgment affirmed.

FOOTNOTES

1.   The Commonwealth's motion to strike is denied as to the defendant's supplemental appendix. The transcripts therein were part of the trial record and were submitted in accordance with our rules.

2.   There is no indication in the record that the defendant renewed his motion to dismiss at any point, and therefore we do not consider any delay from the date the motion judge denied the defendant's motion to dismiss to the trial date.

3.   We note that the motion judge's reference to 212 excludable days corresponded with the Commonwealth's calculation that there were 212 excludable days.

4.   Again, the parties did not produce transcripts of the relevant hearings. We note that the defendant, as the appealing party, bears the burden of producing a record appendix that is adequate for appellate review of his claims. See Mass. R. A. P. 16 (a) (9) (A), as appearing in 481 Mass. 1628 (2019); Mass. R. A. P. 18 (a) (1) (D), as appearing in 491 Mass. 1603 (2023). See also Chokel v. Genzyme Corp., 449 Mass. 272, 279 (2007).

5.   We do not address the other offenses charged in the original complaint because both were dismissed before trial, rendering probable cause moot as to those counts. See, e.g., Carrington v. Commonwealth, 455 Mass. 1014, 1014-1015 (2009).

6.   According to the defendant, Herbert evaded prosecution in this case by testifying against him. We disagree. The video recording supports the Commonwealth's conclusion that Herbert's actions did not warrant prosecution.