Poplar man sentenced to over 3 years in prison for sexual abuse, machete attack

A Poplar man who was indicted on two unrelated charges was sentenced this week to 18 months followed by five years of supervised release for the first charge, and to 26 months followed by three years of supervised release for the second, Acting U.S. Attorney Mark Steger Smith said.

Eithan Toby McKay, 22, pleaded guilty in January 2026 to one count of sexual abuse of a minor and, in a separate indictment, to one count of assault with a dangerous weapon. 

U.S. District Judge William W. Mercer presided.

The government alleged in court documents that when McKay was 19, he engaged in a sexual relationship with a 13-year-old girl and got her pregnant. The following year, McKay attacked his brother with a machete, leaving him with deep lacerations.  

In September 2024, law enforcement received information about a young teenage girl who was pregnant. In an interview with investigators, the girl identified McKay as the father and said the two met on social media and started hanging out at the girl’s house in Poplar. They engaged in a sexual relationship that resulted in the girl getting pregnant when she was 13 and McKay was 19.

In a separate incident, McKay showed up to a Brockton residence with a machete and attacked his brother. A 911 call shortly after 2 a.m. on March 4, 2025, reported the incident, with the caller telling the dispatcher, “Someone just hit my son over the head with a machete and he’s bleeding.” When asked by the operator is the attacker was still in the house, the caller said, “He just walked in the living room. He’s drunk. It’s Eithan McKay.”

The victim had serious injuries to his head, arm, and shoulder and was bleeding heavily. The man told responders that his brother Eithan had slashed him with the machete because he had told Eithan he wanted him to leave.

The U.S. Attorney’s Office prosecuted the case. The FBI and Fort Peck Tribes Department of Law and Justice conducted the investigation.