( CNN ) -- Murder charges were filed Tuesday against a man accused of killing the pregnant wife of a Marine in California . Erin Corwin , 19 and three months pregnant , had been missing since June 28 after she said she was going to Joshua Tree National Park to scout trails . Over the weekend , searchers found her body about 140 feet down a mine shaft . Her former neighbor , Christopher Lee , 24 , was arrested Sunday in Alaska . He is awaiting extradition to California . He faces a murder charge and the special circumstance allegation of `` lying in wait , '' which means he could face life in prison without parole or death , if found guilty , according to San Bernardino County District Attorney Michael Ramos . `` The decision regarding which penalty will be sought will be made after a full review of the facts and evidence in the case , '' he said . Lee had been a suspect from the beginning . Corwin did n't go to Joshua Tree National Park on the day she disappeared , police said in a statement of probable cause written in July . Instead her car was found a few miles from where she lived next door to Lee and his wife , Nicole . Detectives found footprints next to Corwin 's abandoned car that led to tire tracks . Investigators said those tire tracks were the same width and same width apart as the tires on Lee 's Jeep . According to the court document , several people , including a friend of Erin Corwin 's in Tennessee , told investigators that Corwin and Lee were having an affair . He admitted to kissing her but told detectives the two had never had sexual intercourse . Lee also told police that on the day Corwin disappeared he had gone hunting . More than 100 mine shafts were searched before a sheriff 's team found Corwin 's body . Authorities used cell phone information to narrow the search area to 300 square miles . The area included remote land belonging to the federal government 's Bureau of Land Management .
Jason Lee , 24 , was arrested in Alaska , is seeking extradition to California . He is accused of killing his former girlfriend , Jennifer Corwin , 24 . Her body was found over the weekend in a mine shaft .