The turf he protected stretched from Stanton Park on Capitol Hill, up through the bustling H Street corridor and to the southern edge of Gallaudet University.

D.C. Officer Jamal P. Shaw always seemed content, never stressed. In a short time, he worked the day, night and midnight shifts. And he never forgot the job he took nearly three years ago was one of service, not ad­ven­ture.

“He had a uniform, but he had a heart too,” said one of his best friends, Janice Malloy.

On Friday afternoon, Shaw, 27, was killed while off duty and riding a motorcycle in Clinton, Md. He was headed toward his family home, just eight minutes away.

On Monday, D.C. Police Chief Peter Newsham paid tribute to Shaw outside a police substation in Southeast Washington.

The chief met privately with officers on Shaw’s shift, to try, as he said, to “help them with their grief.” Before Newsham ducked inside, he said, “If Jamal is looking down on us, I think the last thing he would like to see is to see us be sad, because he spent his life trying to make others happy.”

The crash that claimed Shaw’s life occurred shortly before 3:30 p.m. in the 9100 block of Piscataway Road, near Branch Avenue. Prince George’s County police said Shaw was heading west when he was forced to take evasive action to avoid colliding with a vehicle that was “changing lanes in front of him.”

Police said Shaw’s motorcycle went down, slid on its side and was struck by a vehicle being driven east. Shaw was pronounced dead at a hospital. The driver of the car that struck Shaw stopped; police said they were still searching for the driver of the car that had changed lanes.

“We would really appreciate it if [the driver] would come forward,” Newsham said on Monday, directing people with information to call either police in the District or in Prince George’s County. Authorities said it is unclear if the motorist who changed lanes is at fault, but investigators would like to talk to that person.

Shaw, who grew up in Prince George’s County, where his parents still live, had been residing with his girlfriend in Southeast Washington. He joined the force in 2015 and was assigned to the First District. He is survived by his parents, two sisters and a brother. He had a degree in criminal justice from the University of Maryland at Eastern Shore, and his friend said he planned to return to school, perhaps the University of Maryland, for a master’s degree, with an eye toward climbing the ranks of the D.C. Police Department.

“This was not a guy who would sit around in the car and do nothing,” Newsham said. “He was one of those guys who always tried to put a smile on your face. From all accounts, he was one of the hardest-working folks that we had over here.”

D.C. Police Cmdr. Morgan C. Kane, who runs the First District, which includes Eastern Market, Union Station, Capitol Hill and parts of downtown, agreed with Malloy that the young officer always seemed happy. “When he came into the room, you understood he had a big smile; he had a big personality to go with it,” Kane said. “He was a go-getter, and he wanted to perform well.”

Malloy said she first met Shaw about 15 years ago, just as he was breaking into his teens. Shaw was her best friend’s son. “He was very outspoken and energetic,” Malloy said. “He really wanted to make the city and his community safer. He enjoyed his job, and he took it personally.”