Santa Clara Police Lt. Mike Sellers says Jing Hua Wu was arrested without incident in Mountain View on Saturday.
Wu had been missing since the Friday afternoon shootings at the offices of SiPort Inc., a company that develops digital radio semiconductors.
Police confirmed that Wu had been let go this week from his job as a product test engineer.
Wu is being booked into Santa Clara County Jail, where he will be held on three murder counts.
The shootings happened around 4 p.m. at a company called SiPort, one of many businesses in an office park at Scott Boulevard and Montgomery Drive.
Investigators have identified the victims as 56-year-old Sid Agrawal, SiPort's chief executive officer, Brian Pugh, 47, the company's vice president of operations and Marilyn Lewis, 67, the company's head of human resources.
Police think 47-year-old Jing Hua Wu walked inside building number seven, suite 102, and shot the three victims.
Wu escaped before police arrived. They shut down exits and questioned everyone leaving by car.
Armed police also scoured Wu's Mountain View neighborhood and surrounded his house thinking he might go home to his wife and children. Police stayed with them through the evening.
"It's just really surprising that someone in this neighborhood unfortunately could have that experience happen to them today and unfortunately make some bad choices," said Lori Markward, a neighbor.
Wu's neighbor, Rajesh Rathi, works at Sun Microsystems.
"I'm in a state of shock. I mean, especially with the news that my company is announcing 6,000 layoffs and this shooting being related to layoffs," said Rajesh Rathi, a neighbor.
ABC7 spoke to an expert on workplace violence who says a bad economy can lead to these kinds of incidents.
"I think we're probably going to see a little bit more of this and I attribute that not to the frustration of losing a job, but I think there's kind of a culture of fear that's out there, not knowing what's happening in the economy. And when that mixes with this kind of emotional chemistry that we're talking about, you can easily have an escalation to an event," said Garry Mathiason, an employment and labor lawyer.
Mathiason says you should watch for direct threats against an individual or an individual's family and report them. Many companies now have programs in place for dealing with this kind of behavior.