Forty-one-year-old Lloyd Hill of Nockamixon Township pleaded guilty to two counts of first-degree murder on Monday, the day his trial was supposed to begin in Bucks County Court.
He was immediately sentenced to life in prison without the possibility of parole.
Hill has been behind bars since the Jan. 27 slayings of his estranged wife and her boyfriend at the apartment they shared.
Investigators said he ambushed 43-year-old Frederick Tarantino outside and beat him to death with a baseball bat, then went inside and fatally stabbed 36-year-old Stefanie Hill.
Prosecutors had planned to seek the death penalty if Hill was convicted.