A former Navy submarine technician has pleaded guilty to strangling his girlfriend and their 5-month-old daughter in Groton four years ago.

Charles A. Davis Jr. pleaded guilty Wednesday to two counts of murder and has agreed to a 72-year prison sentence.

Davis strangled 20-year-old Belinda Parker after a fight in her apartment on Branford Avenue in Groton on Jan. 30, 2004.

Police say Davis choked Parker with his hands then used his belt to strangle her. After Parker died, police say Davis strangled the baby.

The 25-year-old Davis is to be sentenced on May 28 in New London Superior Court.