RENO (AP) - Prosecutors have filed three new charges against a former Marine accused of killing a college woman and sexually assaulting another.

27-year-old James Michael Biela was arrested on Nov. 25 and initially charged with strangling 19-year-old Brianna Denison early this year and abducting and sexually assaulting another woman in December 2007.

On Friday, Biela also was charged with the January rape of Denison, the November 2007 attempted sexual assault of another student and the October 2007 rape of yet another woman.

Police say all four attacks occurred on or near the University of Nevada, Reno, where Biela worked on a project as a pipe fitter.

Washoe County District Attorney Richard Gammick says his office was in the process of reviewing whether to seek the death penalty in the case.

Denison, a sophomore at Santa Barbara City College in California, was abducted while sleeping at a friend's house over winter break from school.

Her body was found Feb. 15 in a Reno field. At the scene, investigators found two intertwined pairs of women's thong underwear.

(Copyright 2008 by The Associated Press. All Rights Reserved.)