The gunman who killed a woman at Citibank’s office complex in Tampa before being shot dead by a security guard targeted the campus because he was angry over a $2,500 debt collection.

Police in Florida identified the shooter on Thursday as Jacob Pearson. He called an attorney affiliated with Citibank and threatened to shoot up the office about three hours before Wednesday’s shooting, Hillsborough County Sheriff Chad Chronister said.

Pearson, 35, told the lawyer that he needed to cancel a court hearing over his debt “unless you want me to go over there with my AR-15, my bulletproof vest and my insanity,” according to Chronister.

The gunman then drove from his home in Orlando to Citibank’s suburban Tampa campus about 90 miles (144 kilometers) away, where 3,200 employees work. He crashed his car through a fence and plowed into a courtyard where employees were eating lunch.

Pearson got out of his car with a rifle and shot the first employee he saw, Chronister said. She was identified as 41-year-old Leann Selman, who worked in human resources for Citibank.

An executive who is part of Citibank’s armed security team shot the gunman five times and Pearson was pronounced dead at a hospital. Chronister said the gunman had 90 rounds of ammunition and shot 15 rounds before his rifle jammed.

He then returned to his car for a handgun.

“He was there intent on one purpose, and that purpose was to hunt any human being he could find and kill them,” Chronister said.

Witnesses describe panic on campus

Thousands of panicked Citibank employees were evacuated from campus and TV footage showed long lines of workers streaming out of office buildings as more than 365 officers swarmed the complex.

David Dzien, a Citibank vice president, told The Associated Press he was heading back to work after lunch when he saw the gunman’s sedan crash through a fence about 150 yards (137 meters) from him. He said an “incredible clatter” followed that he later realized was gunfire.

People near the wrecked car began to run and scream, Dzien said, and he sprinted into the building and evacuated through a fire escape.

“I can still hear the particular type of scream,” he said, “and I’m still trying to process it, frankly.”

He said the shooting came on a day when “VIPs” who don’t normally work at the complex were present for a “quarterly review.”

“All of a sudden, I heard people come, people screaming,” another witness told local CBS affiliate WTSP. “Heard some people running around, and then I saw a big group of people, panicked faces, and then I heard three shots.”