In an action instituted by a father against a city and police officers arising from his detention during investigations prior to his child's death, grant of summary judgment for defendants is affirmed where: 1) although the detention was unsupported by a reasonable suspicion of criminal activity, the officer made a reasonable mistake as to his actions so as to be afforded qualified immunity; 2) procedures adopted by the city do not violate federal law or direct its employees to do so; and 3) defendants are entitled to emergency response immunity under Iowa Code sections 670.12 and sections 670.4(11).