Robert Guastamacchia has covered Chelsea in posters seeking help to find his brother Peter's killer. View Full Caption DNAinfo/Mathew Katz

CHELSEA — Robert Guastamacchia has taken the search for his brother's killer into his own hands.

Guastamacchia, 51, has covered street poles, signs and walls all over Chelsea with hundreds of posters asking for details of the May 16 hit-and-run death of his brother, Peter Gustamacchia, 53.

"Please help me find the person who killed my brother," the signs say, along with a recap of the tragic crash at the northwest corner of West 24th Street and Eighth Avenue.

Peter Gustamacchia, who walked with a cane after a work-related accident a few years ago, was on his way to catch a cab to the Port Authority Bus Terminal when he was struck by a vehicle traveling north at about 5:15 a.m., his brother and police said.

The car allegedly fled the scene and Peter was declared dead at Bellevue Hospital three hours later, according to police.

Gustamacchia has put up new signs every day since his brother's death in the hopes of finding anyone who can help the investigation.

"I'm not a cop," he said.

"I don't have a badge. I have nothing to go on — you don't get many people out there that early. Something like that, it's five seconds and it's over."

Gustamacchia said he and his brother were roommates in the Chelsea apartment where they grew up.

"He was a very quiet guy, he kept to himself, but he was well liked," Gustamacchia said.

The case was initially investigated by the 10th Precinct, but was given over to the NYPD's Highway Patrol. Police have few leads in the case, Gustamacchia said.

He added that while he's leaving most of the investigation to the police for now, he's beginning to lose faith that they'll find his brother's killer.

"They've got limited resources, but that car must have crossed the Post Office or Penn Station," he said. "There are so many cameras there. Why wasn't the video pulled and viewed?"

Still, he hopes to find a store or building owner who might have footage of the car continuing up Eighth Avenue.

Anyone with information is asked to call the NYPD's Crime Stoppers Hotline at 800-577-TIPS.