A 6-year-old boy who lived on the Pascua Yaqui Indian Reservation near Tucson is dead after a man tried to exorcise a demon from him Thursday, according to a federal complaint.

The man, Pablo Martinez, was arrested, charged with first-degree murder and is in custody. Martinez is identified as the boy's father and husband of Romelia Martinez, the boy's adoptive mother, by The Associated Press.

Pablo Martinez told police and the FBI that within the last week, he had noticed that “his son … had a demon inside of him,” according to the criminal complaint. While giving the boy a bath, he “saw something evil” in the child and “knew that he had to cast the demon out.”

On Thursday, police and fire officials from the Pascua Yaqui tribe arrived at a home on the reservation in response to a call about a child who was burned. FBI officials also responded.

Police found Pablo and Romelia Martinez standing outside the home and asked them what had happened. Romelia Martinez said “something to the effect of, ‘He can tell you,’” according to the complaint.

Pablo Martinez told police the boy had been acting demonic, a characterization that the mother agreed with. He told police he “needed to save him” and so he poured hot water down the boy’s throat, the complaint read.

Romelia Martinez told police that her husband had offered to bathe the boy and another child in the home, whom police did not identify. At some point during the bath, that other child left the room crying, according to the criminal complaint.

When the boy's mother heard a gurgling sound in the bathroom, she came by and found the bathroom door locked. She unlocked it and went inside to find Pablo Martinez holding her son under the running faucet of hot water.

Romelia Martinez said she screamed at him to stop, but he responded that “he had to do it.” She called a pastor, who didn’t answer; she then called 911. She said her husband tried to perform CPR on the boy and poured cold water on him.

Pablo Martinez estimated that the boy had been underwater for between five and 10 minutes, according to the criminal complaint.

When officials found the boy inside the house, he was naked and propped up on a pillow in a back bedroom, the complaint stated. He didn’t appear to be breathing.

The boy was taken to Banner University Medical Center in Tucson, where he was pronounced dead. He had burns covering about 15% of his body.

"On Thursday, September 26, 2019, the Pascua Yaqui Community suffered the loss of a child. As a close-knit community this loss weighs heavy on all of our hearts," according to a tribal statement issued Tuesday afternoon.

Pascua Yaqui Police Department and the FBI are continuing to investigate the incident, the tribe confirmed. Pascua Yaqui Police Department Victim Services Section and Behavioral Health Services are working with the tribal leadership to ensure that we provide every means of support and assistance.

Counseling and support services are available at our Centered Spirit Program, which can be reached at 520-879-6060.

"We ask that you respect the family’s privacy during this period of mourning," the statement reads.

According to the Pascua Yaqui tribe, Pablo Martinez is not an enrolled member of the tribe, the complaint read. Romelia Martinez and the boy are both tribal members, according to the complaint.

Pablo Martinez has been charged with first-degree murder. He has been assigned a public defender, Michael John Martinez Areinoff.

Areinoff said he has no comment on the case at this time.