What is the test for finding a municipality liable for failing to act in the context of a civil case?

2010). Second, where acts or omissions causing the constitutional injury amount to official policy of the municipality. Id. Finally, where an official has ratified the unconstitutional decision or action of an employee of the municipality. Id. at 1250. "A custom can be shown or a policy can be inferred from widespread practices or 'evidence of repeated constitutional violations for which the errant municipal officers were not discharged or reprimanded.'" Pierce v. County of Orange, 526 F.3d 1190, 1211 (9th Cir. 2008).

To find a municipality liable for a failure to act, the plaintiff must show that an employee of the municipality violated his constitutional rights, that the customs or policies of the municipality amount to deliberate indifference, and those "customs or policies were the moving force behind" the violation of plaintiff's constitutional rights. Long v. County of Los Angeles, 442 F.3d 1178, 1186 (9th Cir. 2006). For a custom or policy to be the moving force behind the constitutional violation, it must be "closely related to the ultimate injury." Long, 442 F.3d at 1190 (citations omitted). For plaintiff to prevail on a claim that the municipality failed to adopt and implement a policy, he must show that the failure to adopt was deliberately indifferent and that the deliberate indifference was a moving force behind the violation of his constitutional rights. Id. at 1186.