Edward Crawford Jr. is the subject of one of the most memorable photographs taken during the Ferguson protests. In it, he wears an American flag T-shirt while hurling a blazing can of tear gas. The photo was reproduced on T-shirts and mugs. It helped The St. Louis Post-Dispatch win a Pulitzer Prize for photography. It even became a tattoo.

The image led to a life of recognition for Mr. Crawford. Strangers approached him for his autograph. People sought him out for selfies. But friends say Mr. Crawford was never able to distance himself from the fame. “People would run up and want to take pictures with him, and he would be polite,” said Tony Rice, an activist who met Mr. Crawford during the protests. “But I don’t think I ever heard him mention it. It wasn’t something he talked about.”

And then, more than one year after the photo was taken, St. Louis County filed Ferguson-related charges against Mr. Crawford for interfering with a police officer and assault. The case was pending in May 2017 when Mr. Crawford was found dead with a gunshot wound to the head in the back seat of a car. He was 27.

Mr. Crawford never made any money from the photo. “We were working through ‘how to deal with being famous,’” Jerryl T. Christmas, his lawyer, said. On the day Mr. Crawford died, he had missed a meeting with Mr. Christmas about a plea deal that would have allowed him to avoid jail time.

Though Mr. Crawford’s death has been ruled a suicide, questions have persisted among those who knew him. He is one of at least six activists with connections to Ferguson who have died violently, some from apparent suicides.