Whether a district attorney's office may be held liable under §1983 for failure to train prosecutors based on a single Brady violation without proof of a pattern of similar violations.
Holding
No. Thompson did not establish that Connick was deliberately indifferent to a known or obvious need for additional Brady training.
Reasoning
A municipality is liable under §1983 only for its own unconstitutional policies or customs, not under respondeat superior for its employees' misconduct. A failure to train can qualify as municipal policy only when the failure reflects deliberate indifference to constitutional rights and actually causes the injury. Deliberate indifference is a demanding standard: the policymaker must disregard a known or obvious consequence of the training decision.
Ordinarily, a plaintiff proves deliberate indifference through a pattern of similar constitutional violations by untrained employees. Such a pattern puts the policymaker on actual or constructive notice that the existing training is deficient in a particular way. Without that notice, retaining the program ordinarily cannot be treated as a conscious municipal choice to cause constitutional violations.
Thompson did not identify a pattern of similar Brady violations. Four prior Louisiana convictions had been reversed for Brady violations by prosecutors in Connick's office, but none involved undisclosed blood evidence, crime-lab reports, or physical or scientific evidence. Those cases therefore did not give Connick notice of a need to train prosecutors specifically to avoid the nondisclosure that occurred in Thompson's robbery case.