Accused Facebook killer enters plea in San Mateo County court

3 mins read

A man who allegedly recorded a homicide victim’s last moments and uploaded the video to his Facebook page appeared in a San Mateo County courtroom Monday for an arraignment. 

Mark Stephen Mechikoff, 39, of Pacifica, pleaded not guilty to murdering Claribel Estrella inside her San Mateo apartment on July 26. 

Mechikoff waived his right to a speedy preliminary hearing and was escorted out of the Hall of Justice courtroom. He remains locked up in a Redwood City jail with no bail. 

Prosecutors say that Mechikoff stabbed Estrella to death and felt proud of his crime so he uploaded the video to Facebook to show what he had done. 

“He then filmed it and posted it on his Facebook account. She was on the ground, and still alive, still moving a little bit,” District Attorney Steve Wagstaffe told the press.

Prosecutors added enhancements to the first-degree murder charge because of the Facebook video. “By putting it on Facebook … he felt a certain pride,” Wagstaffe said.

The veteran district attorney said, “That is the first time I’ve ever heard of anything like that. Certainly it’s never occurred in San Mateo County. It’s a horrific crime.”

Law enforcement was first notified of the gruesome video on July 26. A woman who was Facebook friends with Mechikoff called a sheriff’s office in Nye County, Nevada and said she had just watched a video of a woman covered in blood and lying on the ground. 

The woman added the video was filmed in the last place where she knew Mechikoff lived. 

Nye County deputies “pinged” a cellphone number associated with the Facebook account. Investigators then tracked the cellphone’s location to a large apartment complex in San Mateo, California. 

San Mateo Police Department officers went door-to-door looking for the victim. The three-hour search ended when officers found Claribel Estrella’s body, stabbed to death on the kitchen floor. 

At that time, the killer had already fled the crime scene. 

Two hours later, police found Mechikoff in San Jose and arrested him. 

It was believed that Mechikoff and Estrella knew each other. A friend of the victim said Estrella briefly dated her accused killer before breaking off the relationship. 

“He seemed like a bad guy, that’s why she was his ex. She mentioned he was abusive,” Knuist told the press.

Judge Lisa Novak granted a request from defense attorneys who said they need more time to investigate the case. Mechikoff will return to court on September 15 at 1:30 p.m. to set a timeline for the case moving forward.

Investigators are still looking through evidence to establish a possible motive.


Charlene is a Bay Area journalist who hails from the small community of Fresno. Drawing from her experience writing for her college paper, Charlene continues to advocate for free press and local journalism. She also volunteers in all the beach cleanups she can because she loves the water.