RIVERSIDE, Calif. (AP) — Two men who used high-powered rifles to kill three wild burros in Southern California’s Mojave Desert more than two years ago pleaded guilty on Monday to federal charges related to the shootings, prosecutors said.

The men wore tactical gear including night vision goggles as they targeted the burros in a remote area northeast of Barstow on Nov. 6, 2021, the U.S. Attorney’s Office said in a statement.

John Feikema of Yorba Linda, California, and Christopher James Arnet of Loveland, Colorado, each pleaded guilty to one felony count of possessing an unregistered short-barreled rifle and one misdemeanor count of maliciously causing the death of a burro on public lands, the statement said.

Wild burros are protected under federal law. They are also an iconic symbol of the American Southwest, dating to their days as pack animals during California’s Gold Rush.

Feikema, 36, fired at least four shots, while Arnet, 32, fired at least five, investigators said.

“One burro was shot near its spine towards its hind legs, which paralyzed the burro’s hind legs and caused the animal severe pain before it died. A bullet removed from that burro was fired from Arnet’s firearm,” the statement said.

The weapons, unregistered “AR-style” rifles, were seized at each man’s house, prosecutors said. As part of their plea agreements, Arnet and Feikema agreed to surrender the guns, over 4,000 rounds of ammunition, night vision goggles and other tactical gear.

At sentencing set for July 8, each defendant faces a statutory maximum sentence of 10 years in federal prison for the firearm violation and up to one year for the burro deaths, according to prosecutors.