DENVER -- Twenty-two minutes before Adams County Prosecutor Sean May was gunned down outside his Denver home, he was on the phone with his friend, Defense Attorney Doug Romero.

Romero said he had just represented a suspect in a Peeping Tom case, and there were rumors that a angry relative of the victim was out to get the suspect and Romero.

"(May) was warning me, saying, 'Hey man, watch out. Take care of yourself,'" said Romero. "He was that type of individual, caring about everybody and everything."

Romero said May should have been more concerned about his own safety.

Just a few minutes after the phone call, May had been killed.

Romero is convinced the killer is a vengeful relative of someone May put behind bars, but he said the people who know what happened aren't talking.

He said police have strong leads, and there has been a grand jury investigation into the matter.

"I don't think they have probable cause. I don't think they know exactly who did it and I don't think they have direct physical evidence saying who this individual is,” said Romero.

On Wednesday, authorities released a sketch of a man wanted in connection with May's slaying. They apparently had the sketch for the last year but said they didn't release it to the public earlier because they were following leads on it.