San Jose police on Wednesday night shot and killed a 24-year-old man with a history of mental illness after he gunned down his ex-girlfriend's parents in their Willow Glen home.
Police said Mirza Tatlic shot and killed Naren Prabhu, a vice president of engineering at Juniper Networks in Sunnyvale, and Prabhu's wife Wednesday night inside their home.
Tatlic had once dated the couple's daughter, police said.
Officers responded to the 1000 block of Laura Ville Lane around 9 p.m. Wednesday after the homeowners' adult son reported that his parents had been shot, according to police Chief Eddie Garcia.
A heavy police presence, including the department's Mobile Emergency Response Group and Equipment, or SWAT team, descended on the house.
Upon arrival, police saw that a man was dead near the front door, with at least one gunshot wound. They later learned the victim's wife was inside the house with the couple's 13-year-old son and the suspect.
Soon thereafter, the suspect released the teenager. He was physically unharmed, Garcia said.
The police department's tactical negotiations team began a dialogue with Tatlic to "get him to surrender peacefully," Garcia said, but "he refused."
Neighbors heard them giving orders.
"We just heard over the bullhorn, 'Come out with your hands up!” Kim Vostermans said, noting that she heard "all this screaming."
Neighbor Holly Troche added, "We did hear the police say, 'Let the boy go.'"
Tatlic then appeared in a window and pointed his handgun at officers on the arrest team. Afraid for the lives of his fellow police officers and other victims in the house, at least one officer discharged his weapon, striking Tatlic, Garcia said.
"The suspect had been in a dating relationship with the victims' adult daughter," Garcia said. The pair's relationship ended last year and the woman was not home at the time of the shooting, which "really surprised the victims for all intents and purposes."
Investigators are currently "drilling down on motive, drilling down on weapons used," Garcia added. Tatlic's gun was not registered to him, Garcia said, and police are still investigating how he was able to get his hands on it.
Garcia said that Tatlic had priors of domestic violence and drinking under the influence. He also had a history of mental illness and his ex-girlfriend, the slain couple's daughter, had an active restraining order against him, the chief said.
There also was a possible advance warning on Tatlic's Instagram page from a couple weeks ago. He wrote: "No mercy on the ones that love you most."
"One could infer that it is over a failed relationship, however the extent of how that really got to this individual still remains to be investigated and thoroughly vetted," Garcia said. "Obviously this relationship had something to do with his motive. We just don’t know the extent of it."
No one else was injured, Garcia said. One of the couple's daughters lives in the area, but not necessarily in San Jose. Another was traveling back to the area on Thursday. Police are not searching for any outstanding suspects.
"It’s a horrible, horrible crime," Garcia said. "Again, dealing with someone who is mentally ill, who had choices, [but] he didn’t give this family choices, he didn't give my officer a choice. And it’s just a tragic, tragic incident perpatreted by evil. I don’t know how else to put it."
While police continue to investigate what led up to the tragic shooting, neighbors told NBC Bay Area they’re heartbroken for the victims' family.
"Wonderful people, and it’s very unfortunate to have that happen to anyone in this neighborhood of willow glen," neighbor Marcus Watson said.
The officer who opened fire, a 17-year veteran, has been placed on paid administrative leave, per department policy.
The Santa Clara County District Attorney’s Office and the San Jose Police Department's Homicide Unit are conducting a joint criminal investigation.
The case is being monitored by the San Jose Police Department's Internal Affairs Unit, the City Attorney’s Office, and the Office of the Independent Police Auditor.
It was the San Jose Police Department's second officer-involved shooting in as many days. On Tuesday night, police shot and killed a man when responding to a family altercation in East San Jose. He charged toward officers clutching a large knife.
NBC Bay Area's Bob Redell and Michelle Roberts contributed to this report.