NYPD detectives are investigating whether an ex-con suspected in the grisly slaying of a 31-year-old woman killed her in a drug dispute, cops and sources said Tuesday, a day after an angry mob targeted the man as authorities took him into custody.

Police charged Chad Irish with concealment of a human corpse after he was identified as the man in a motorized wheelchair allegedly caught on video leaving the body of homeless advocate Yazmeen Williams next to several trash bags outside an apartment building on E. 27th St. near Third Ave. in Kips Bay just before 5 p.m. Friday.