Police are searching for a suspect who murdered an unarmed man today after chasing him into a brownstone on a tree-lined block in the Fort Greene section of Brooklyn.

The suspect shot the victim, Lawrence Sumpter, 37, three times, twice in the buttocks and once in the stomach, before fleeing, police officials said.

The shooting, only blocks from Pratt Institute, unfolded just before noon when the suspect shot at least two rounds at the victim in the middle a street. Dodging a bullet, Sumpter ran for cover into a brownstone that was undergoing renovations at 22 Clifton Pl. The suspect followed and fired at him at least two more times on the first floor of the building.

A craftsman working in the brownstone, Sam Saliman, who heard the shots and fled to the basement from the second floor where he was installing a door, was the first to find the wounded victim.

“I went upstairs and saw the guy,” he said. “He looked dead.”

Mr. Saliman said police arrived at the house within ten minutes. The victim was rushed to Brooklyn Hospital where he later died.

City detectives spent the morning interviewing witnesses in the neighborhood. While they have a description of the suspect, the motive is unclear, a police source said.

Sumpter, who a neighbor said ran a window installation business, was raised in the neighborhood but had moved several years ago.