Nearly 15 years later, police identify the victim of a brutal killing as a 14-year-old girl

Orange County police identify teenage girl who was murdered in 2009

Nearly 15 years later, police in Orange County have identified the victim of a brutal murder and kidnapping as a 14-year-old girl.

She was found dead in an Irvine parking lot on the morning of Sept. 5, 2009, and for more than a decade, her name remained unknown even as a pair of brothers faced murder charges in her killing. One of them is serving time behind bars after being convicted of first-degree murder in 2022 while the other will be retried in the future. Both men were charged in 2010 with her murder, with a special sentencing enhancement for murder in the commission of a kidnapping.

Marcia Shirree Thomas, 14, has been identified as the victim through DNA evidence gathered by investigators. She had been reported missing from Reno, Nevada, according to police.

A sketch of Marcia Shirree Thomas, 14, made after she was killed in 2009. Her name went unknown for nearly 15 years even as two men were charged with murdering her. Orange County District Attorney's Office

"Marcia's family remains in our thoughts during this difficult time," Irvine Police Chief Michael Kent said in a statement. "We appreciate the agencies that have assisted in providing crucial information to support the case and the family."

DNA evidence also led investigators to the two men who authorities say killed Thomas, including the man a jury found guilty of murdering and kidnapping her. Zenaido Valdivia-Guzman was convicted on Nov. 15, 2022, more than a decade after prosecutors first filed charges against him and his brother, Gabino Valdivia-Guzman.

Along with her name, Thomas's age went unknown in the years since her death. In prior accounts of the killing, prosecutors and law enforcement officials have described her as believed to be an adult.

On the night of Sept. 4, 2009, the Valdivia-Guzman brothers were driving through Santa Ana when they came across Thomas near the intersection of Harbor Boulevard and First Street, authorities said. According to prosecutors, Gabino convinced the girl to get in, but once inside the van, she realized another man was in the back seat and started screaming as she tried to escape.

After pulling her into the back of the van, Zenaido started beating her in the face and strangled her to death. Meanwhile, his brother allegedly drove them to Irvine, where he took her body out of the vehicle in the parking lot of an industrial complex.

"The two defendants are accused of dumping the victim's body in the parking lot, dousing her with gasoline from a canister in the van, and setting her body on fire," reads a 2010 statement from the Orange County District Attorney's Office, which first announced the charges against them.

From there, prosecutors said, they took Thomas's cellphone and fled the area. 

The next morning, employees showing up for work found her partially burned body and called police. Underneath her fingernails, investigators collected DNA evidence which was entered into the database of the Orange County Crime Lab.

Over a year after Thomas's body was found, on Nov. 5, 2010, Zenaido was linked to her killing through DNA he submitted in connection with a 2009 misdemeanor conviction for domestic violence. A day later, detectives found him in a Santa Ana shopping center and arrested him. He happened to be with his brother Gabino, whose alleged involvement was discovered after further investigation. He was also arrested.

That same day, prosecutors filed murder charges against the brothers. At the time, Zenaido was 24 and Gabino was 31.

When Zenaido was convicted by an Orange County jury in 2022, 12 years after his arrest, Orange County District Attorney Todd Spitzer vowed to keep looking for the identity of the victim, her name and age still a mystery.

"This woman did not deserve to have her life ended in such a horrific way by a complete stranger," Spitzer said in a statement at the time. "We may not know yet who this woman was, but we will never stop trying to identify her and we will never stop pursuing justice for her and everyone who loved her."  

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