PHILADELPHIA (AP) — Police said Friday that they have issued an arrest warrant for a 19-year-old acquaintance in the death of a Philadelphia journalist who went from sleeping on the street to working for the mayor to writing urgent columns on the city’s most pressing social issues.

Josh Kruger, 39, was shot and killed at his Philadelphia home early Monday.

Police believe the acquaintance killed Kruger, but could not give a motive, they said. They have video of the suspect in the area of Kruger’s home before the shooting. Kruger knew the suspect and had been trying to help him get through life, police said.

Kruger was shot seven times at about 1:30 a.m. and collapsed in the street after seeking help, police said. He was pronounced dead at a hospital a short time later.

The slaying was felt deeply at City Hall and among people involved in the many causes he cared about: addiction, homelessness, HIV and LGBTQ+ advocacy, journalism and bicycling, to name a few.

“One of the worst parts of being homeless in urban America is feeling invisible. When people don’t recognize your humanity, you begin to question it yourself,” he wrote in a 2015 column for The Philadelphia Citizen, just three years after he himself slept outside a law firm near Rittenhouse Square.

In more recent columns, he condemned City Council members as cowards for banning supervised injection sites in most parts of the city; dismissed debates about politically correct language over homelessness as beside the point; and, in a final column, dove into the city’s collective grief over the sudden death last month of Temple University’s acting president JoAnne Epps.

“To many Philadelphians, Epps was someone they truly loved — in part because she loved them,” he wrote, calling it a “solemn honor to write about someone after they’ve died.“

Mayor Jim Kenney, in a statement Monday, said that Kruger’s writing and advocacy showed how deeply he cared for the city, adding that “his light was dimmed much too soon.”

Kruger handled social media for the mayor and communications for the Office of Homeless Services from about 2016 to 2021. He left city government to focus on writing projects.

He wrote at various times for Philadelphia Weekly, Philadelphia City Paper, The Philadelphia Inquirer and other publications, earning awards for his poignant and often humorous style.

On his website, he described himself as a “militant bicyclist” and “a proponent of the singular they, the Oxford comma, and pre-Elon Twitter.”