Half Moon Bay, California - The man charged with killing seven co-workers in a pair of mass shootings at farms in Half Moon Bay admitted to his crimes in a jailhouse interview Thursday.

Chunli Zhao (66) spoke to NBC Bay Area’s Janelle Wang, telling the reporter he had experienced "years of bullying" and working long hours at the farm before he took a semiautomatic handgun and opened fire on his co-workers Monday.

"He admitted that he did do it," Wang said in the report.

San Mateo County District Attorney Stephen Wagstaffe told The Times in an interview that although he could not go into details in the case, Zhao’s comments to the TV station were "consistent with what he told law enforcement."

In the 15-minute interview, Zhao also said he had been suffering from "some sort of mental illness" and was "not in his right mind" at the time of the shooting.

Zhao said he planned to turn himself in to law enforcement when he drove to the San Mateo County Sheriff’s Office and was writing a note in his car before he was taken into custody. Wang said Zhao also told her that he regretted the deadly incident.

Law enforcement officials allege the rampage took place after Zhao "snapped" because of a still-unknown grievance.

The suspect faces felony charges that could make him eligible for the death penalty, authorities said.