A young mother who was nearly decapitated on the street in front of her San Carlos apartment last Thursday morning was likely killed with a samurai sword, according to the San Mateo County District Attorney's Office.

Authorities alleged that Karina Castro, 27, died after 33-year-old Jose Raphael Solano Landaeta, who is Castro's ex-boyfriend, used the sword, "slashing numerous times causing the victim's head to be almost severed."

Castro attended Menlo-Atherton High School in Atherton between 2009 and 2011 before getting a GED.

The attack occurred around 11:40 a.m. on Thursday, Sept. 8, in the area of Magnolia Avenue and Laurel Street near downtown San Carlos in front of multiple witnesses on the street.

Landaeta of Hayward is alleged to have then walked away from the scene and placed the bloody sword in his car, which was parked two blocks away, according to the district attorney's office.

When San Mateo County Sheriff's Office deputies arrived, they found Castro dead on the street and arrested Landaeta, who is said to havereturned to the scene shortly afterward. He has been charged with murder.

In a press conference Sept. 8, Sheriff's Office Lt. Eamonn Allen said that investigators had confirmed that a "stabbing instrument" had been the weapon that was used in the killing. That "stabbing instrument" has now been identified as a samurai sword.

Allen said that due to the "shocking nature" of the scene, deputies who first arrived "were a little beset by it." He added that the county would be providing them and witnesses at the scene with counseling services.

Landaeta, who has a history of mental illness, was meant to be arraigned in court on Monday, but his defense attorney asked a judge to allow a doctor to examine his client's mental fitness and whether he was competent to stand trial. Criminal proceedings have been suspended until doctors have examined Landaeta, according to the district attorney's office. In the meantime, the court has issued a protective order against Landaeta to have no contact with Castro's two children, 7 and 18 months.

On Friday, Sept. 9, San Carlos Mayor Sara McDowell was joined by the City Council to express their "deepest condolences" to the two young children.

"Yesterday, our community was shocked by the tragic murder of a young mother in our community. Thanks to the quick reaction by neighbors calling 911, San Carlos deputies were able to quickly respond and immediately take a suspect into custody. It appears the victim and the suspect knew each other."

The city of San Carlos and the Community Foundation are partnering to accept and hold in trust donations for the future benefit of Castro's children.

"As we mourn together and process this event as a community, please remember to take care of yourself, and to check in on your neighbors and loved ones. There is no doubt that the resilience and heart of the City of Good Living will shine through the darkness of this tragedy."

Anyone with information about the case is asked to contact Det. Brandt at (650) 333-8195 or dbrandt@smcgov.org.