Seven witnesses helped identify a man, Gregory Boyd, who they said fit the description of Walker’s killer, the suit said.

Frank Drew served 24 years for murder and was exonerated last year. He is suing Evanston police and Cook County officials.

A police report identifies the suspect as 68-year-old Ronald Walker, of Fort Worth, who was arrested on suspicion of aggravated assault, according to a police report. Police found a steak knife in ...