First Circuit
Holloman v. Clarke, 208 F. Supp. 3d 373, 376 (D. Mass. 2016) (stating that “cases before 2012, when the conduct here allegedly occurred, clearly establish that an officer has a duty to intervene when another officer uses excessive force against a pretrial detainee”).
Davis v. Rennie, 264 F.3d 86, 114 (1st Cir. 2001) (“The cases involving police and prison guards clearly established at least the same duty for mental hospital staff at a state institution.”).
Eighth Circuit
Smith v. Conway County, Ark., 759 F.3d 853, 861 (8th Cir. 2014) (“At the time Smith was tased, ‘it was clearly established that a jail official violates a detainee’s due-process rights if the official knows that another official is using excessive force against the detainee but fails to intervene.’”).
Edwards v. Byrd, 750 F.3d 728, 733 (8th Cir. 2014) (“At the time of the incident, it was clearly established that a jail official violates a detainee’s due-process rights if the official knows that another official is using excessive force against the detainee but fails to intervene.”).