A California street ambassador walking his daily crime deterrence “beat” in San Francisco was fatally shot by a shotgun-wielding man after he asked the individual to stop using drugs outside of a library where children were present, local officials say.

“The suspect didn”t like that,” Urban Alchemy spokesperson Jess Montejano told reporters this week about UA ambassador Joey Alexander’s shooting death last Friday outside of the San Francisco Main Library.

“They exchanged some words, [the suspect] pulled a shotgun out of his bag, and shot him in the torso,” Montejano said, according to local CW affiliate KRON.

Cops identified the suspect as 42-year-old Edmund Bowen.

Alexander, 60, had been working for UA as a street ambassador for two years following a 23-year stint in prison.

“That was his beat, in front of the main library,” Montejano said. “He showed up to work every day when it was his shift.”

Alexander’s brother, Marvin Alexander, told the San Francisco Chronicle that Joey “said he liked his job” and that he, like many of the former convicts who work for the UA, was trying to turn his life around by helping out in the community as a street ambassador.

“He said you have to really know how to deal with these people,” Marvin Alexander said. “You can’t tell nobody what to do, you just ask them.”

Officials say children were near the library when Joey Alexander tried to get the man to stop using illicit drugs in the area. The shotgun blast from the suspect hit Alexander in his leg which led to it being amputated. He reportedly died Tuesday from health complications.

“It’s just so sad to me that you do all that time and come home … and then never have a problem until this one idiot comes along, and that’s all it ever takes, is one idiot,” Marvin Alexander told the Chronicle. “One nut comes by and pulls a stunt like that and kills my little brother. It’s just terrible.”

Court records show that police arrested Bowen on Saturday and booked him into jail on suspicion of homicide. He currently is facing a murder charge, per records.

“There’s definitely some fear amongst Urban Alchemy practitioners right now,” Montejano said. “It’s very easy to see themselves in Mr. Alexander.”

Ronald Carter, a close friend and Urban Alchemy worker who met Alexander while serving time at Ironwood State Prison in Riverside County, described him to the Chronicle as a “quiet and humble man who never raised his voice.”

“Everybody is going to miss him dearly,” Marvin Alexander said.

UA is known for working with the city in some of San Francisco’s roughest areas. Mayor Daniel Lurie sent out a statement Wednesday saying, “Our ambassadors dedicate their lives to the work of helping those on the street. Joey Alexander gave his life for it.”