Jose Rafael Solano Landaeta, 34, was found guilty of the brutal crime which occurred in the city of San Carlos, in San Mateo County in September 2022.
He killed his partner Karina Castro, the mother of his then-one-year-old daughter, outside her apartment, reportedly due to an argument over Snapchat messages.
At the time of the murder, local media reported that Castro was beheaded by a sword in the attack, with additional cuts all over her body and numerous cuts on her neck.
The verdict was returned on Monday in a Redwood City courtroom, in California.
According to KGO-TV, Landaeta and Castro were in an ongoing relationship, but law enforcement sources said that the victim had taken out a temporary restraining order against the suspect in April 2022.
Jose Rafael Solano Landaeta (34) found guilty by a jury of 1st degree murder with use of a sword.
Landaeta beheaded his girlfriend on the street in San Carlos on September 8, 2022. pic.twitter.com/H4AuncdEgD
— San Mateo County District Attorney (@SanMateoCoDA) November 20, 2023
Family members of the victim told the outlet that Landaeta was schizophrenic and on medication. His family reportedly confirmed this through his attorney.
Both law enforcement and Castro’s family say that Landaeta had been violent with Castro, leading her to request the restraining order. The San Mateo District Attorney said Castro never called police when Solano violated the order.
Following the incident DA Steve Wagstaffe said he was not “in no way critical” of Castro for not having alerted authorities.
“There’s something called the cycle of domestic violence and this is one of them,” he said.
San Mateo County Sheriff’s Lieutenant Eamonn Allen said deputies who responded to the scene were upset “based on the nature of the crime,” and were receiving support. Witnesses were also offered counseling, he said.
“There were some civilians that did see it and those people were traumatised in their own right by seeing this horrific crime,” Mr Wagstaffe later added.
According to KGO-TV, who later interviewed Landaeta in prison, he admitted to killing Castro, but claimed it had been in self-defence.
Landaeta could face 26 years to life in prison, according to Mr Wagstaffe.