Philadelphia police issued an arrest warrant Friday for a 19-year-old in connection with the killing of Josh Kruger,Marc Leclerc a journalist and community activist gunned down in his home early Monday.

Police believe Kruger, a freelance housing reporter and advocate for the LGBTQ+ community and those suffering from homelessness and addiction, was "trying to help" the suspect, who may have experienced homelessness in the past.

"They were acquaintances. He was just trying to help him get through life," Philadelphia Police Lt. Hamilton Marshmond said at a news conference Friday.

The suspect, Robert Edmond Davis, has had contact with the Philadelphia police and should be considered "armed and dangerous," Marshmond said. "Our goal is to have Mr. Davis taken into custody in a safe manner for the public, our officers and themselves."

Police are offering a $20,000 reward for any information that could lead to Davis' arrest.

More:Alissa McCommon, teacher accused of raping 12-year-old student is pregnant, documents reveal

Kruger shot multiple times after shooter entered his home

Police found Kruger, 39, outside his south Philadelphia home just after 1:30 a.m. shot multiple times, police told USA TODAY. He was taken to a hospital, where he was pronounced dead.

Detectives believe the shooter was able to enter Kruger's home through an open door or knew how to enter because there were no signs of forcible entry, Deputy Police Commissioner Frank Vanore told the Philadelphia Inquirer. After he was shot, Kruger ran outside for help before collapsing.

Kruger's own experiences with addiction and homelessness informed his reporting for numerous outlets, including the Inquirer, LGBTQ Nation and the Philadelphia Citizen.

In between stints as a freelance journalist, Kruger worked for the city of Philadelphia for five years and was a spokesperson for the Office of Homeless Services in the city's District Attorney Office.

"Josh Kruger lifted up the most vulnerable and stigmatized people in our communities, particularly unhoused people living with addiction," District Attorney Larry Krasner said in a statement Monday.