A Marion man awaiting trial for allegedly physically and sexually abusing his girlfriend's 9-month-old son has pleaded innocent to attacking a detention officer.

During his arraignment Thursday in Flathead County District Court, Shane Phillip Nickerson, 21, pleaded not guilty to assault on a peace officer, a felony.

According to court documents, three detention officers were moving Nickerson - whom court papers describe as "combative" - to a new cell on Jan. 14 when Nickerson pushed one of them in the chest, knocking him backwards.

The officers pushed Nickerson into the cell, but he charged the still-open door and then punched the detention officer in the torso several times, prosecutors allege.

After the incident, Nickerson reportedly took off his shirt and challenged the detention officer to a fight.

Nickerson has been in the Flathead County Detention Center since August.

He is awaiting trial next month on charges of sexual intercourse without consent, sexual assault, aggravated assault and criminal endangerment.

According to court documents, sheriff's deputies were called to Kalispell Regional Medical Center on Aug. 9 after medical personnel found his girlfriend's child with bruises on his head, a bloody mouth, and injuries consistent with sexual abuse.

After being treated at Kalispell Regional Medical Center, the child was airlifted to Sacred Heart Hospital, where he was admitted with severe brain injuries from partial asphyxiation.

A second medical exam found that the boy, who has since returned to the Flathead, had suffered other injuries consistent with sexual abuse.

The child's mother later told detectives that Nickerson had volunteered to watch the child while she slept in that morning.

If convicted of all charges in the abuse case, Nickerson could face up to 230 years in prison and a $200,000 fine.

A conviction for assaulting a peace officer could carry up to an additional 10 years in prison and $50,000 in fines.

Also on Thursday, defense attorney Carolyn Gill withdrew her motion to reduce Nickerson's $750,000 bail.

Gill had no comment on the new charges.

Reporter Nicholas Ledden can be reached at 758-4441 or by e-mail at nledden@dailyinterlake.com