Police have a suspect in custody, but no motive as to why Brian G. Chapman Jr. was gunned down while on the front porch of his Guilford Street home early Wednesday morning.

"It certainly sounds, at this point, that Mr. Chapman was doing nothing but waiting for a ride to go to work," said Chief of Detectives Dennis J. Richards.

Joshua J. Mitchell, 24, of LaSalle Avenue, has been charged in connection with the fatal shooting of Chapman, 39, a Niagara Frontier Transportation Authority bus driver.

Mitchell is being held on two felony weapons counts, including one for a previous conviction in 2007, as Homicide Squad Detective Sgt. James P. Lonergan and Detective James A. Lema build a murder case against him, Richards said.

A .38-caliber revolver recovered near the scene is believed to be the murder weapon.

Chapman was on his porch, in the 300 block of Guilford, just before 5 a.m. Wednesday, waiting for a ride to work, the chief said. Several shots were fired at him from a passing car.

Chapman was rushed to Erie County Medical Center, where he died from his wounds. It's the city's third homicide of the year.

Ferry-Fillmore District Officer Dennis R. Gilbert happened to be on patrol in the vicinity of Guilford when he heard the shots fired.

Soon after, Gilbert spotted a gray Saturn Ion, believed to be involved in the shooting, and stopped the car at Herman and Genesee streets. The .38-caliber handgun allegedly was tossed from the rear of the car and was recovered at Guilford and Genesee by Officer Jeremy W. Connolly.

Mitchell, a passenger in the back seat of the Saturn, was booked by Gilbert and Officer Brian O. Griffin.

Mitchell is being held in the Erie County Holding Center as he awaits a court appearance in Buffalo City Court.

Meanwhile, news of Chapman's death was greeted with sadness at the NFTA.

Chapman had worked out of the authority's Cold Spring bus garage, where his colleagues were given the tragic news as they came into work.

"Everybody knew Brian," said Jeffrey Richardson, the vice president of Transit Union Local 1342.

Chapman had worked at the NFTA for 12 years, officials said. He drove buses on routes all across the city and worked as a clerk in the office when people were on vacation or the staff was short-handed, Richardson said.

"He was friendly. Happy. A great guy," Richardson said. "He would do anything he could for anybody. Brian was loved by every worker here. Nobody spoke an ill word about Brian. He is going to be one that is truly missed."

Chapman liked to be the life of the party, Richardson said, and often talked about his family, including his father, Brian Sr., who works as a rail controller with the NFTA's Metro Division.

"He enjoyed his job, and he was appreciated by the customers that he picked up each and every day, and he will be missed by the employees and his customers," NFTA spokesman C. Douglas Hartmayer said. "It's a tragic loss."

News Staff Reporters Lou Michel and Denise Jewell Gee contributed to this report.