SAN QUENTIN, Calif. (KGTV) - A serial killer and former Camp Pendleton Marine who was sentenced to the death penalty may have killed himself at San Quentin State Prison Friday, prison officials said. 
 
 Andrew Urdiales, 54, was found unresponsive during a security check of his cell late Friday night, according to staff members. Correctional officers performed CPR but Urdiales was pronounced dead less than an hour later. 
 
 An autopsy will be performed but his death is being investigated as a suicide, officials said. 
 
 RELATED: Serial killer convicted of Southern California murders 
 
 An Orange County jury sentenced Urdiales to death one month ago for the murders of five women in San Diego, Mission Viejo, Palm Springs, and Cathedral City in the 1980s and 90s. Urdiales had been previously convicted of killing three Illinois women in the 1990s. 
 
 Urdiales’ victim in San Diego, 31-year-old Maryann Wells, was shot in the head in a deserted industrial complex on Second Ave. in downtown San Diego in 1988. Investigators said Urdiales had sex with Wells then took back the $40 he had paid her. Urdiales left behind a condom that eventually provided a DNA link, implicating him in the case. 
 
 Another death row inmate was found dead Sunday night at San Quentin. Virendra Govin was convicted of killing four people by setting their home on fire in 2004. Govin's death is also being investigated as a suicide. Prison officials do not believe it was related to the death of Urdiales. ||||| A serial killer and former Camp Pendleton Marine convicted of slaying eight women in two states in the 1980s and ‘90s, including a San Diego woman in 1988, was found dead over the weekend in his cell on death row at San Quentin State Prison in a suspected suicide, officials said Monday. 
 
 Andrew Urdiales, 54, was sentenced to death on Oct. 5 and had been on death row at the prison on the San Francisco Bay for less than a month. Correctional officers found him unresponsive in his cell about 11:15 p.m. Friday during a security check. 
 
 Correctional officers unsuccessfully performed CPR on Urdiales, who was alone in his cell in the prison’s Adjustment Center, a housing unit for problem prisoners. 
 
 He was pronounced dead at 12:01 a.m. on Saturday. 
 
 “His cause of death is pending the results of an autopsy; however, his death is being investigated as a suicide,” Lt. Samuel Robinson with the California Department of Corrections and Rehabilitation said in a statement. 
 
 Prison officials offered no other details about his death. 
 
 Urdiales was sentenced to death last month by Orange County Judge Gregg Prickett, who affirmed an earlier death penalty decision by an Orange County jury. That same jury had convicted Urdiales in May of five counts of murder in San Diego, Riverside and Orange counties. 
 
 He’d previously been convicted of three slayings in the Chicago area and sentenced to death, but the death penalty was later abolished in Illinois, so he was re-sentenced to life without parole. He was moved to Orange County in 2011 to be tried for the five Southern California murders. 
 
 Urdiales’ nine-year killing spree began in 1986, and he carried out four of the killings while enlisted in the Marine Corps and stationed at Camp Pendleton in San Diego’s North County and Twentynine Palms in San Bernardino County, according to prosecutors. 
 
 After he was discharged from the Marines and returned to his hometown in Chicago, he killed a fifth woman while visiting Southern California, and he killed three women in Illinois. 
 
 Among his victims was 31-year-old San Diego resident Maryann Wells, who was killed with a gunshot to the head and dumped in a downtown San Diego alley on Sept. 25, 1988. Urdiales was stationed at Twentynine Palms at the time. 
 
 According to news reports from the time of Urdiales’ 1997 arrest in Illinois, Wells’ murder was not initially linked to a series of other unsolved murders because it did not fit the pattern of the other victims being strangled and dumped in a remote, rural area, the Los Angeles Times reported. 
 
 Dom Najolia / AP In this April 25, 1997 file photo, Andrew Urdiales walks in police custody at police headquarters in Chicago. Urdiales was convicted of murdering five women in Southern California and three in Illinois. He died of suspected suicide in his death row prison cell early Saturday. In this April 25, 1997 file photo, Andrew Urdiales walks in police custody at police headquarters in Chicago. Urdiales was convicted of murdering five women in Southern California and three in Illinois. He died of suspected suicide in his death row prison cell early Saturday. (Dom Najolia / AP) 
 
 Urdiales was stationed at Camp Pendleton when he took the life of his first victim, 23-year-old Robbin Brandley, who was attacked as she walked to her car in a dimly lit parking lot following a piano concert on Jan. 18, 1986, at Saddleback College in Mission Viejo. 
 
 Before he was sentenced to death last month, Urdiales said he wanted to express his “sincere apologies” to jurors, the judge, prosecutors, victims' families and his own family for having to hear the “gory” details of his crimes. 
 
 Urdiales even praised the Orange County prosecutors who tried him, and to the jurors, he said, “I understand how they voted. If I were a juror on my case I would probably have done the same thing. There's no hard feelings.” 
 
 He also apologized to a woman who escaped from his car after he terrorized her in 1992 in Riverside County. 
 
 Orange County District Attorney Tony Rackauckas said in a statement Monday that “Urdiales was a monster who did not deserve to breathe the same air we all enjoy.'' 
 
 Rackauckas said Urdiales ``remained a callous coward until the end as he robbed the victims' families of the right to be present when the state put him to death.'' 
 
 California has 740 prisoners on death row but has not executed an inmate since January 2006. 
 
 About 23 hours after Urdiales was discovered in the Adjustment Center, a second death row prisoner died of suspected suicide in a different area of the prison. 
 
 Virendra Govin, 51, was found unresponsive in his cell in the North Segregation housing unit around 10:15 p.m. on Saturday and pronounced dead 15 minutes later. He and his brother, Pravin Govin, were each sentenced to death for the 2004 murders of a business rival, two of her teen children and her mother-in-law. 
 
 The suspected suicides of Govin and Urdiales were not believed to be related, according to prison officials. 
 
 Since 1978, when California reinstated the death penalty, 25 death row prisoners have committed suicide and 79 have died of natural causes, prison officials said. 
 
 City News Service contributed to this report. 
 
 Twitter: @Alex_Riggins 
 
 (619) 293-1710 
 
 alex.riggins@sduniontribune.com 
 
 UPDATES: 
 
 8:05 p.m.: This article was updated with background information about Urdiales’ crimes. 
 
 5:10 p.m.: This article was updated with additional details about the suicide of death row inmate Virendra Govin. 
 
 This article was originally published at 4:35 p.m.
– Death was apparently preferable to life on California's Death Row for serial killer Andrew Urdiales. The 54-year-old inmate was found dead in his cell at San Quentin State Prison on Friday night and authorities believe he killed himself, News 10 reports. Urdiales was sentenced to death by an Orange County judge Oct. 5 for killing five women in California between 1986 and 1995, four of them while he was stationed at Marine Corps Base Pendleton, the San Diego Union-Tribune reports. It was the third time he had been sentenced to death: He was sentenced to die in 2002 for two murders in Illinois, but the sentence was commuted to life imprisonment, along with all other death sentences in the state, by Gov. George Ryan in 2003. Urdiales was then tried for a third Illinois murder and sentenced to death again in 2004. After Gov. Pat Quinn abolished the death penalty in Illinois in 2011, Urdiales was extradited to California. Urdiales "remained a callous coward until the end as he robbed the victims' families of the right to be present when the state put him to death," Orange County DA Tony Rackauckas said in a statement. Less than 24 hours after the death of Urdiales, a different Death Row prisoner was found dead of an apparent suicide in a different area of San Quentin. Authorities do not believe the death of 51-year-old Virendra Govin, who was sentenced to die in 2005 for killing a business rival, her two children, and her mother-in-law, is related to that of Urdiales. (California hasn't executed anybody since 2006, and San Quentin is running out of space.)