An off-duty Customs and Border Protection officer admitted to threatening 3 tribal employees with a rifle, telling them he 'shoots first, asks questions later'

• An off-duty CBP officer admitted to assaulting three Blackfeet Tribe employees.
• The employees were on the officer's property to test creek water and said they got permission from his wife.
• The officer pointed his rifle at the employees and told them he "shoots first, asks questions later."

An off-duty US Customs and Border Protection officer has admitted to pointing his rifle at three tribal employees who were collecting water samples on his property, telling them he "shoots first, asks questions later," according to court documents.

Harrison Garrett Alvarez, a 30-year-old CBP officer in Montana, signed a plea agreement July 16 admitting to three counts of simple assault. The Justice Department announced the agreement in a July 22 statement.

Prosecutors said the altercation began on July 24, 2019, when three Blackfeet tribal members, who were also employees with the tribe's environmental office, arrived on Alvarez's property to collect water samples from the Cut Bank Creek.

Alvarez's property is located within the Blackfeet Indian Reservation, and the tribal employees said they had received permission from Alvarez's wife to be on the property. They said they had also conducted the same water tests on the property three other times that same season, according to prosecutors.

The tribal members told authorities they heard a rifle shot ring out as they began collecting samples. They told Alvarez his wife had given them permission to be there, but the off-duty officer disagreed.

Prosecutors said Alvarez's wife later told authorities she had instructed the employees to speak with Alvarez directly to get permission, but added that she had also pointed out their truck to Alvarez on the morning of the incident and told him it most likely belonged to "the water people."

Alvarez eventually allowed the employees to leave unharmed, but warned them that he "shoots first, asks questions later," according to prosecutors.

"Even after they told him they would go, Alvarez, while still leveling the rifle at the victims, ordered them closer to him and demanded they drop their equipment," prosecutors said. "All three victims believed Alvarez was going to shoot them."

A judge will sentence Alvarez on November 18. Prosecutors said Alvarez faces a maximum of six months in prison, a $5,000 fine, and one year of supervised release for each of the three counts.

CBP told Insider in a statement that Alvarez is still employed, but "in a non-law enforcement capacity pending final disposition in the case."