Merced County jail inmate was stabbed 20 to 30 times, investigators say

The man who allegedly stabbed a fellow inmate this week at the Merced County jail has been identified by authorities as a 37-year-old Atwater man in custody awaiting trial in connection with a 2015 homicide case.

The inmate, David Lastra, also made headlines last year when his effort to escape from the Merced County jail failed.

Lastra on Tuesday used a 7-inch piece of metal that he filed down on the floor to stab 19-year-old Joseph Henry Dominguez, Merced County Undersheriff Jason Goins said.

Lastra and Dominguez were on the recreation yard at the downtown Merced County Jail with several other inmates when Lastra jumped Dominguez, knocking him to the ground and stabbing him 20-30 times, Goins said.

“There was apparently an incident outside the jail months ago involving the two families that led to the assault in the jail,” Goins said. “We don’t believe the attack was gang-related.”

Dominguez remained hospitalized in serious condition on Wednesday.

Dominguez was jailed in connection with the Los Banos stabbing death of Guillmer Diaz in 2015. Dominguez was arrested in the homicide case when he was a minor. He’s pleaded not guilty to multiple felony charges, according to court records.

Lastra has pleaded not guilty in the 2015 slaying of Richard Valentine, with whom Lastra previously shared a jail cell. Valentine was working as a police informant when Lastra allegedly killed him. In January 2016, Lastra cut a hole in the jail’s concrete ceiling in an effort to escape, but he never made it out.

Lastra remains in jail on more than $2 million bail.

This story was originally published June 7, 2017 at 2:54 PM with the headline "Merced County jail inmate was stabbed 20 to 30 times, investigators say."