Cesar Laurean, 23, of Las Vegas, was found guilty of killing Lance Cpl. Maria Lauterbach, 20, of Vandalia, Ohio, in December 2007. The two were assigned to the same logistics unit at Camp Lejeune, the base in Jacksonville that is home to about 50,000 Marines.
The former Marine was sentenced to life in prison without the possibility of parole.
The victim's mother, Mary Lauterbach, read a statement before the judge imposed the sentence. She told Laurean to look at his mother and see the pain in her face.
"I feel so sorry for your daughter. She will have to live with the shame that her father is in prison for murdering not one but two people," Mary Lauterbach said.
Defense lawyer Dick McNeil told the court Laurean would appeal. The judge ordered the state's appellate defender's office to represent Laurean's appeal.
Laurean also faced three other charges of robbing Lauterbach of her bank ATM card, and of theft and attempted fraud for allegedly trying to use it to withdraw cash. He was found not guilty of the robbery charge, but Laurean was convicted on the fraud and theft charges.
The jury of seven women and five men deliberated for three hours since Monday before convicting Laurean.
Laurean was eventually cleared of the rape accusation, and a Marine buddy testified Laurean told him the sex was consensual.
Prosecutors had argued Laurean wanted to get rid of the woman because their encounter threatened to destroy his military career. Even if the sex was consensual, Laurean could have been punished because it is against Marine Corps rules to have sex with a subordinate.
McNeil had argued prosecutors failed to prove Laurean swung the crowbar that fractured Lauterbach's skull. Laurean's wife, also a Marine, could have exploded when Lauterbach appeared at the couple's home on the day she disappeared. Authorities described Christina Laurean as a cooperating witness and have not charged her with any crime.