PHILADELPHIA — Philadelphia police have arrested a city man in the February slaying of a well-known community activist.

Thirty-night-year-old Nelson Giddings was already behind bars in an unrelated case when he was charged Monday night with murder, robbery and other offenses.

The victim, 65-year-old Winnie Harris, was acting executive director of a nonprofit group that plants and tends trees. Her body was found inside her home on Feb. 3.

Police say Giddings and a suspect still on the loose broke into the wrong house. They say Harris wasn’t the intended target.

It’s not clear if Giddings has a lawyer who could comment on the charges.