"It's really sad and scary that people have access to guns so easily that a domestic dispute could lead to loss of life so quickly," said witness Vishnu Vithala.
The three-year resident lives one floor above the murder scene, at the Crescent Village apartment complex in North San Jose. He said his wife heard gunshots early Sunday morning and, by the time he awoke and looked over his balcony, he heard the final shot.
San Jose police investigators, Monday, said a domestic dispute between a husband and wife turned deadly when an apartment security guard intervened and was shot.
"I'm sure he's trying to do the right thing. Sees somebody in distress and wants to go help and intervene. and unfortunately, the suspect committed a very heinous act and killed him," said police spokesman Sgt. Christian Camarillo.
Detectives said after the suspect killed the security guard, he shot and killed his wife, and then took his own life.
The triple loss of life, taking place in an exterior parking lot of the tony apartment complex, has been unnerving to some neighbors.
"I was pretty afraid, honestly. Kind of shaken. It seems like a very random act. And that's not something you want to see anywhere. But I feel for the victims of course," said neighbor Ajit Pung.
One resident said the murdered guard patrolled the complex parallel to Zanker Road and Vilaggio Street.
"He was a very nice guy. He used to be, basically to make sure nobody got through this door. Like, if he saw somebody who was staying here too long and not able to get in, he would come and say 'what's going on? Who are you?,'" said Vithala.
Apartment complex general manager Kim Robinson, Monday afternoon, emailed a statement to KTVU which read, "Our entire team is deeply saddened by the lives that were lost in this tragic incident and our thoughts are with their families. We are offering counseling to our employees during this difficult time."
Investigators said the couple had six children, ages 12-months to 10 years. The kids are now staying with their maternal grandmother, as detectives try to unravel how a marital dispute led to three deaths.
"Looking down from there (my balcony) every day. And now we don't know, like even after a week or 10 days or a month, will we ever be able to look at (the area) in a normal way," said Vithala.
Detectives continue gathering surveillance video and witness statements to try to determine what led up to the conflict.
The couple's names, and the name of the slain security guard have not been released by the county coroner.
Jesse Gary is a reporter in the station's South Bay Bureau. Follow him on Twitter @JesseKTVU and Instagram @jessegontv