The father of a 22-year-old man who police say killed a monkey after breaking into an Idaho zoo says he believes the tragedy was a drunken prank that got out of hand and “turned into a horrible situation.”

Michael J. Watkins was arrested Monday, and authorities plan to charge him with a pair of felonies: burglary, for allegedly breaking into Zoo Boise, and grand theft, for taking and killing a monkey.

The suspect’s father, Jerry Watkins, tells the Idaho Statesman that his son is “not a malicious monkey murderer.”

Jerry Watkins says friends of his son have told him Michael Watkins was drunk and wanted to try to get a picture with the monkeys when he broke in to the zoo. He thinks the monkey must have attacked his son, and his son defended himself.

The patas monkey died early Saturday of blunt-force trauma.

Michael Watkins’ arraignment is set for Wednesday.