SAN FRANCISCO (AP) — A man suspected of going on a three-hour shooting rampage in Northern California and killing 81 animals, including miniature horses, goats and chickens, pleaded not guilty to animal cruelty and other charges.

Vicente Arroyo, 39, made his first court appearance Thursday after Monterey County Sheriff deputies arrested him earlier in the week for allegedly using several weapons to shoot the animals being housed in pens and cages on a lot in the small community of Prunedale.

The animal owners do not want to be identified or speak with the media, Monterey County Sheriff Commander Andres Rosas told The Associated Press Friday.

“I went out there, and it was a pretty traumatic scene. These were people’s pets,” he said.

One of the miniature horses belonged to the owner of the lot where the animals were housed, the other 80 belonged to someone who rented the land to house their pets, Rosas said.

According to court records, Arroyo was charged with killing 14 goats, nine chickens, seven ducks, five rabbits, a guinea pig and 33 parakeets and cockatiels. Arroyo is also charged with killing a pony named Lucky and two miniature horses named Estrella and Princessa, KSBW-TV reported.

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Some animals survived the shooting that lasted several hours but had to be euthanized because of the severity of their injuries, Rosas said.

Rosas said Arroyo lived in a camper in a vineyard next to the lot where the animals were kept and that a motive is not yet known.

Authorities received multiple 911 calls around 3:25 a.m. Tuesday reporting shots being fired in Prunedale, an incorporated community about 8 miles (13 kilometers) from the city of Salinas, he said.

Deputies who arrived on the scene could hear shots being fired, and a shelter-in-place was ordered for a five-mile radius.

Monterey County S.W.A.T. members were sent in, and the sheriff’s office also requested drone assistance from the nearby Seaside Fire Department and Gonzales Police Department, Rosas said.

Officers in an armored vehicle arrested Arroyo without incident, he said.

Deputies found a crashed pickup truck and recovered eight firearms, including long rifles, shotguns and handguns, at the scene. After executing a search warrant on his camper, they found another seven firearms, including an illegal assault weapon and two ghost guns, and about 2,000 rounds of various calibers of ammunition, Rosas said.

Prosecutors charged Arroyo with dozens of charges involving animal cruelty, willful discharge of a firearm with gross negligence, illegal possession of an assault weapon, vandalism, drug possession and making criminal threats and terrorizing while being in possession of a firearm as a felon.

“This is obviously the most horrific animal cruelty case we’ve ever seen in this county, I’m sure,” Chief Assistant District Attorney Berkley Brannon told KSBW-TV after the Thursday hearing.

Arroyo’s defense attorney, William Pernik, raised doubts about his mental competency. The judge ordered Arroyo, who is being held on a $1 million bail, to undergo a mental evaluation.

The court will get an update on Arroyo’s mental status in two weeks, the television station reported.