But that was the job. And Murray had been practically born into it. His father, Joe “Reds” Murray, was a cop who insisted on walking a beat along Jewelers Row in his late 50s instead of retiring. Joe’s grandfather and two uncles had been cops, too. “Reds” thought his son might try college after high school, but he headed straight for the Police Academy instead. As soon as he got on the force, he took his grandfather’s old badge number.

Outside of then-Police Commissioner Charles Ramsey, Murray was also one of the best-known cops in the city. Long before anyone else in the Police Department, he used his personal Twitter account to try to show people that he wasn’t much different from any other thirtysomething living in the city; he just happened to wear a badge to work everyday.

His tweets lurched from funny and self-deprecating — “Just had $20 worth of Wawa food on the touch screen then hit cancel and walked out. Big step for me.” — to offering particulars about unsolved crimes. This approach won him thousands of followers and some glowing media coverage, but it pissed off some of the department’s older bosses, who didn’t think a detective should be releasing information to the public without going through the chain of command.

Blowback over his Twitter stardom had thus far prevented Murray from reaching his ultimate goal: to work in the Homicide Unit.

One uncle, Dennis Murray, had been a sergeant in Homicide, and Joe came to view the unit as something that was available only to the department’s best investigators.

But mostly he wanted to land there out of admiration for his father, who developed a reputation in the 1980s and ’90s for being particularly adept at capturing murder suspects in the Badlands of North Philly. “Reds” Murray was so good, locking up more than 50 accused killers by his count, that a notorious gunman named Jose “Little Bert” DeJesus once put a contract out on his life.

That was the kind of work Joe wanted to do. But for now, he was stuck chasing criminals west of the Schuylkill.

He grabbed his phone and answered the call. A shooting, he was told, had just been reported in West Philly, on Angora Terrace near 55th.

That’s strange, he thought. It was unusual to have somebody shot before lunchtime, even in this city.