In a 42 U.S.C. section 1983 action for damages wherein plaintiff alleged various claims of police misconduct in arresting him, order denying plaintiff's motion to leave to file a second amended complaint and disallowing an expert witness affidavit is affirmed, but summary judgment for defendant on basis of qualified immunity is reversed where: 1) the additional utility extracted from reviewing defendants' records and consulting an expert did not justify plaintiff's delay in seeking leave to amend; 2) the expert affidavit was properly excluded, as plaintiff's failure to comply with Fed. R. Civ. Pro. 26 was both unjustified and harmful to the defendants; but 3) the district court erred by failing to review the full record on summary judgment and misapplied the legal standards for summary judgment.