OFFUTT AIR FORCE BASE, Neb. (AP) — An airman has pleaded guilty to charges that he killed another airman at Offutt Air Force Base near Omaha.

Officials say Airman 1st Class Timothy Wilsey entered the plea Thursday to a charge of premeditated murder. It carries a sentence of life in prison.

Prosecutors say he strangled 20-year-old Airman 1st Class Rhianda Dillard on Aug. 1, 2016. She joined the Air Force after graduating high school near Biloxi, Mississippi.

Three days before Dillard’s body was found in a dormitory, Wilsey was recorded by surveillance cameras walking into it with Dillard and leaving alone a short time later.

Wilsey was arrested 11 days later in Emporia, Virginia. An investigator says a journal written by Wilsey found on him at the time of his arrest described the killing in lurid detail.