WARREN — A Maine State Prison inmate serving time for murder has pleaded not guilty to a new murder charge for allegedly killing another prisoner last spring.

The Bangor Daily News says 49-year-old Franklin Higgins entered a not guilty plea today during his initial court appearance in Knox County Superior Court.

Higgins was charged Friday in the beating death of 51-year-old Lloyd Millett at the Maine State Prison in Warren.

Higgins is serving a 45-year sentence in the 1999 stabbing death of a woman inside her apartment in Kenduskeag.

Millett was serving a life sentence after pleading guilty to strangling two women over a weekend in 1995 while he was working as a farmhand in Turner.