( CNN ) -- A 25-year-old woman has been charged with first-degree murder in the California death of a deployed Marine 's wife , San Diego County authorities said Friday . Jessica Lynn Lopez , 25 , was being held Friday after she pleaded not guilty at her arraignment a day earlier and her bail was set at $ 3 million , said Steve Walker , a spokesman for the San Diego County district attorney . The investigation into the murder of Brittany Killgore , 22 , is ongoing and additional charges could be filed , Walker told CNN Friday . Marine Staff Sgt . Luis Ray Perez , 45 , who was on a date with Killgore when she was last seen alive a week ago , was charged earlier this week with two felonies unrelated to Killgore 's death -- receiving stolen property and possession of an assault weapon -- and he has pleaded not guilty , authorities said . If convicted , Lopez would face 25 years to life in prison ; Perez would face up to three years if convicted , Walker said . The San Diego County Sheriff 's Department said this week that Perez was being `` actively investigated '' in connection with Killgore 's death . `` We believe he knows more than what he initially told us , '' said Sheriff 's Capt . Duncan Fraser . `` We do not believe he is being cooperative with us . '' Killgore , 22 , was seen last Friday night when she left her apartment wearing an evening dress , heading out on the date with Perez , who is based at Camp Pendleton in San Diego County , investigators said . Perez was questioned after a friend filed a missing person report for Killgore and he was later arrested on charges of possession of a stolen assault rifle , authorities said . Investigators later found Killgore 's body in a rural part of neighboring Riverside County . Authorities have not said how she died . Lopez 's relationship to Killgore has been unclear . CNN affiliate KGTV in San Diego reported that authorities found Killgore 's body based on leads stemming from Lopez 's arrest . Lopez was found at a Ramada motel near the San Diego airport Tuesday after paramedics responded to a call for medical help . She was briefly hospitalized with lacerations and then jailed on suspicion of Killgore 's murder . Killgore had recently filed for divorce from her husband , Marine Lance Cpl . Cory Killgore , who was serving with an artillery unit in Afghanistan 's Helmand Province , investigators said . He was granted an emergency leave to return to the United States when he learned his wife was missing . San Diego County District Attorney Bonnie M. Dumanis issued a statement saying : `` This is an ongoing investigation and , as the county 's top prosecutor , my responsibility is to protect the integrity of the case , ensure a thorough investigation , and ultimately hold those responsible in a court of law . ''
Jennifer Lynn Smith , 25 , pleads not guilty to a murder charge in San Bernardino County . Brittany Killgore 's body is found in a rural area of northern Riverside County . She recently filed for divorce from her Marine husband , who was in Afghanistan . Another Marine is also being investigated in the area , authorities say .