HYATTSVILLE, Md. -- Police confirm that a man who shot himself Wednesday at a Hyattsville apartment and later died was under investigation in connection with several rapes in which the attacker met victims online.

Police identified the man as Mark Antonio Humphries, 33, of Suitland.

Police said Humphries visited Craigslist and chat rooms to set up dates with professional escorts. When the women showed up, police say they were attacked by a masked man. The rapes began in August but were not linked until early this year.

Police obtained an arrest warrant for Humphries on Sunday in connection with a July 14 sexual assault on Malcolm Road.

Investigators searched for Humphries and located him Wednesday at about 12:30 p.m. in the 4200 block of Oglethorpe Street.

Humphries barricaded himself inside an apartment when officers tried to contact him, and a short time later, a gunshot was heard coming from inside the apartment, authorities said.

Emergency services personnel found Humphries alone in the apartment with a self inflicted gunshot wound.

He was taken into custody and transported to a local hospital, where he died at about 10:30 p.m.

Sources said that two days ago, police set up a sting to capture Humphries at a motel on Route 1 in College Park, but Humphries eluded police.