AUSTIN—A University of Texas police officer who shot and killed a research animal in March was warned to stay in his car before firing 10 rounds and killing Tony the chimp, according to newly released documents.

In reports obtained by the Austin American-Statesman, UT police officer Paul Maslyk drove his personal car to the Keeling Center for Comparative Medicine and Research when a 140-pound, 17 ½-year-old chimpanzee broke out in March.

Tony escaped from a jungle gym area by jumping more than 15 feet and grabbing the top of a corral wall. Attendants at the center tried to subdue the animal by firing tranquilizers at it, but Tony snatched the gun and broke it, according to a police report. That’s when the animal began to flail its arms and approach Maslyk, police said.

Fearing for his safety, the officer twice shouted “I’m gonna shoot” as the animal approached. He fired while backing away, lost his footing and shot some more as the animal passed by him, police said in their report.

In the supplementary report by police, Lt. Ward Norcutt wrote that Maslyk’s “police training caused him to be more concerned for the safety of others” than for himself when he got out of his vehicle, the paper reported.

But Laura Kelly, a senior animal technician at the center, said in a witness statement that the officer “didn’t know what he was doing—he was gun happy,” the paper reported.

In another witness statement, Dr. William Satterfield said he saw the officer move to “intercept the animal” as “several members of the capture team yelled for him to move away. He proceeded to move in the direction of the chimp as it ran toward the brush cover.”

Satterfield is a professor of comparative medicine at the University of Texas M.D. Anderson Cancer Center’s Department of Veterinary Sciences.

The Keeling Center plans to tighten its security and is considering adding a second wall around the chimpanzee enclosure as well as buying two-way radios, the paper reported.

UT police officers have since undergone training in chimpanzee behavior. The first was in May.

“We took (Tony’s shooting) very seriously,” Wendy Gottsegen, a spokeswoman for M.D. Anderson, told the paper. “There’s been a lot of effort to look at the program hard to make sure that we can prevent this from ever happening again.”

Maslyk did not immediately return a phone message left by The Associated Press.