Few people would have blamed William “Popeye” Blackmon if he’d kept his mouth shut after witnessing, just a few feet away, the shooting death of his good buddy last July.

Instead, he helped lead authorities to his friend’s killer. Nine days ago, on the night of May 26, his family believes, he paid for that decision when he was shot to death, only a couple blocks from the original shooting.

Blackmon, 51, knew the streets and the customs of Buffalo’s East Ferry-Moselle-Grider-Woodlawn area. For some 40 years, he had walked those streets. He was a charmer and a hustler, armed with a gift of gab. And while family members admit he was no saint and had spent some time in jail, he also was known for helping people down on their luck, whether it was giving them a dollar or two or guiding them to the nearest food pantry.

Last July 18, Blackmon watched in horror as close friend Darryl “Bobby” McDavis was shot to death in broad daylight, at East Ferry and Stevens streets. Police have claimed it was a dispute over drugs and possibly a bicycle.

Blackmon saw it all, and he told Buffalo homicide detectives exactly what he witnessed. Late last October, police in Tennessee arrested the key suspect, Wyatt “Chicago” Hayes, who was charged with second-degree murder. Hayes pleaded guilty to first-degree manslaughter on May 17, nine days before Blackmon was killed, law-enforcement officials said; Hayes is scheduled to be sentenced June 14.

“My brother had the guts to stand up and tell them what happened,” said Kimberly Blackmon, one of his sisters.

“We have a heart,” she explained. “When you lose somebody like that, a good friend, by something so senseless, what are you supposed to do? We can’t just shut up.”

William Blackmon may have known his own days were numbered.

A few days before he died, he began sleeping on a chair in his sister’s home.

“My brother was the type of man who wanted to do the right thing,” said another sister, Deborah Irvin. “He took a chance. He knew the consequences. Near the end, he felt he was going to lose his life over this.”

His family has gone public with its plea for someone in the community to do the right thing and come forward with information about his killer, the same way their brother did.

They held a prayer service and vigil Sunday evening in the area where he was shot, stumbled and collapsed, fatally wounded.

On Monday, Kimberly Blackmon and Deborah Irvin issued their own plea to their brother’s killer.

“If you have any pride, any self-worth in yourself, you should come forward and turn yourself in,” Kimberly Blackmon said. “This is going to haunt you, because you took away somebody who was so precious. Popeye never harmed a fly.”

There’s little question that someone saw their brother die. It was a hot night, about 10 p.m., the night before Memorial Day, when many people would have been outside, some on nearby porches in full view of the shooting scene.

Kimberly Blackmon understands that her brother’s death can have a further chilling effect, causing people to fear for their lives if they come forward. If they talk, they can be labeled snitches, and that can put their lives in jeopardy.

But if witnesses don’t talk, then crimes go unpunished.

“You have to talk, because you have to live in these neighborhoods,” she said. “You want peace in your neighborhood. You want to be able to walk the streets.”

Both sisters emphasized that anyone coming forward needs to ask police for witness protection.

Kimberly Blackmon knows who the real culprit is.

“These kids today are more scared to live than they are to die. They’ll kill you at the drop of a dime. They don’t know how to fight, but they know how to pick up a gun.”

Anyone with any information about William Blackmon’s killing may call or text the Buffalo Police confidential tip line, at (716) 847-2255.

His family knows what Blackmon would want, the same thing they want – justice.

“My brother looked out for the community over there,” Irvin said.

“Now,” her sister quickly added, “they should return the favor.”