A Browning man was sentenced Monday to 18 years and nine months behind bars for sexually abusing two girls on the Blackfeet Indian Reservation about 20 years ago.

A jury convicted Michael James Burke, 43, of two counts of aggravated sexual abuse of a child and abusive sexual contact of a child in federal court last year. Chief U.S. District Judge Brian Morris presided over the two-day trial in October.

The U.S. Attorney’s Office alleged that Burke sexually abused two girls, at the time under the age of 12, between 1999 and 2003 in Browning. He threatened both girls and told them no one would believe them if they sought to expose him, court documents said.

In 2017, the victims reported the sexual abuse to authorities.

Both reportedly suffered significant emotional trauma.

“For a good majority of my pre-teens I was afraid for my life and my family’s life because of the threats that were made. If I said anything or told anyone about what happened I was afraid of someone or myself getting severely injured, which is why it took me so long to get help,” said one victim in a statement to the court. “I do my best to avoid anything that triggers all of the horrible memories, which is quite stressful. Having gone through all of this I’m very physically, emotionally, and mentally exhausted. …I’m still healing from all of this and know I will unfortunately be dealing with this for the rest of my life.”

Upon his release from prison, Burke will serve 10 years of supervision, officials said.

Blackfeet Law Enforcement Services investigated the case in conjunction with the FBI.