A 20-year-old man from California, identified as Martin Mendoza Jr., has been charged with murder in relation to the death of his 18-year-old girlfriend, Marissa DiNapoli. The incident reportedly took place after Mendoza confronted DiNapoli about her interactions with a former boyfriend. According to police reports, security footage captured the last moments of DiNapoli with Mendoza, who is alleged to have stabbed her multiple times in the back and left her near a local lake.
The video footage, sourced from a Ring camera and shared by local NBC and ABC affiliate KSBW, showed Mendoza and DiNapoli leaving a residence in Morgan Hill. This was one day before DiNapoli was reported missing and two days before her body was found at Anderson Lake on July 2, as reported by the Santa Clara County District Attorney’s Office.
The details of the footage and the events leading up to DiNapoli’s murder were included in Mendoza’s criminal complaint, obtained by Law&Crime. The complaint detailed the couple descending a staircase together, with Mendoza confronting DiNapoli about her ex-boyfriend. DiNapoli’s apprehension was clearly visible in the video footage.
The Ring camera recorded the couple on June 29. Cellphone ping data showed that DiNapoli and Mendoza left the residence around 9:45 a.m. that day. By 9:52 a.m., DiNapoli’s cellphone was detected moving east on E. Dunne Avenue towards Anderson Lake. Between 9:58 and 10:04 a.m., both DiNapoli and Mendoza’s cellphones were traced to the vicinity of Anderson Lake.
At approximately 10:14 a.m., both phones were tracked moving west on E. Dunne Avenue at Thomas Grade, stopping near E. Dunne Avenue and Heritage Green Park. Mendoza’s vehicle was seen moving westbound on E. Dunne Avenue at Hwy 101 around 10:18 a.m., which was also the last time DiNapoli’s phone showed activity.
DiNapoli did not report for her shift at Starbucks later that day, which was unusual as she typically worked the evening shift. A missing person report was filed on June 30. On July 1, Mendoza’s vehicle was seen on video attempting to cross into Mexico at the San Ysidro border. DiNapoli’s body was discovered the following day, and Mendoza was arrested upon his attempted return to the U.S. on July 6.
DiNapoli was found with five stab wounds to her back. Family members later disclosed that there had been several unreported incidents of domestic violence where Mendoza had physically assaulted DiNapoli. Mendoza was arraigned on charges of murder committed with a deadly weapon, with additional circumstances including causing great bodily injury, being armed or using a weapon, targeting a vulnerable victim, and abusing a position of trust. He was ordered to be held without bond and has not yet entered a plea.