In the summer of 2012, a homeless man named William Greer Jr. was bludgeoned to death in a park in Austin, Texas. Greer’s case remains unsolved, and his daughter is determined to find answers:

“In the weeks that followed her dad’s death, Tangie drove to Austin three times: once to speak to police, once to speak to reporters, and once to commemorate what would have been Greer’s 50th birthday on July 29. On one of those visits, Tangie went to the spot where her father lost his life. She spoke to a transient named Chris who sleeps nearby and asked him if he had seen anything the night of the murder. She knew detectives had already questioned him—and eliminated him from their investigation—but maybe he had forgotten to tell them something that could prove crucial. ‘I was playing detective in a way,’ Tangie told me.

“Chris told her he didn’t remember her dad, but that he did recall another transient sleeping at the same spot before Greer’s murder, and afterward. He gave her a description of the man, and Tangie relayed the information to detectives. But she says they told her Chris wasn’t reliable. ‘If you interviewed him eight times, you’ll get eight different answers,’ a detective said.”