Michael Armstead, 53, was assaulted Nov. 27 at the North Branch Correctional Institution in Allegany County as inmates were on their way to the dining hall, and died at Bon Secours Hospital in Baltimore on Jan. 9.
State police did not release the name of the suspect who allegedly assaulted Armstead, but said charges are pending. The suspect is also serving a life sentence, police said.
Armstead was found guilty in the early 1990s of serial home-invasion rapes in Anne Arundel and Howard counties and was serving six life sentences.