Dion Starr (plaintiff) was an inmate in a Los Angeles County jail. Starr was brutally beaten by several other inmates. Starr claimed that a deputy opened his cell door to permit the attack, rather than attempt to protect him. Starr brought a supervisory liability suit against Sheriff Leroy Baca (defendant) in his individual capacity, alleging that Baca was deliberately indifferent to the dangerous and unconstitutional conditions of Los Angeles County jails. As part of his complaint, Starr alleged several instances of Los Angeles County inmates being injured or killed due to the unconstitutional actions of Baca’s subordinates. Starr alleged that Baca was aware of these instances and had not taken any actions to increase security or otherwise reduce the dangerousness of the jails. The district court granted Baca’s motion to dismiss for failure to state a claim. Starr appealed.