From FourthAmendment.com:
A mental health detention requires “requires only a ‘probability or substantial chance’ of dangerous behavior, not an actual showing of such behavior.’” … Probable cause for involuntary hospitalization may be established from ‘information gleaned from informants[,] … normally the putative victim or eyewitness, unless the circumstances raise doubt as to the person’s veracity.’ … “However, the ‘harm to self or others’ standard is not met by evidence suggesting merely that the person is emotionally disturbed. See Myers, 819 F.3d at 634 (‘A person may be annoyed, uncooperative, and irrational without presenting a danger to herself or of violence to others.’).” “Insofar as plaintiff contends that the undisputed evidence assembled by defendants does not warrant summary judgment under the ‘harm to self or others’ standard, she is correct. Defendants do not identify, nor has the Court found, any cases holding that probable cause existed for a mental health seizure on facts similar to the ones in this case. To the contrary: courts in the Second Circuit generally find probable cause for a mental health seizure only where there were threats of harm to others, suicidal threats, clear evidence of self-harm, the possession of a firearm or other dangerous weapon by a mentally disturbed person, or some combination of those factors. ….” Guan v. City of New York, 2020 U.S. Dist. LEXIS 212611 (S.D. N.Y. Sept. 18, 2020).