Jury selection is scheduled to begin this morning in the trial of a Marion man accused of sexually and physically abusing his girlfriend's baby more than a year ago.

Prosecutors allege 21-year-old Shane Phillip Nickerson severely beat the boy, now almost 2, and then sexually assaulted him.

Attorneys are expected to call police officers, medical professionals and expert witnesses over the course of the five-day trial in front of Flathead County District Court Judge Stewart E. Stadler.

Nickerson pleaded not guilty in August 2008 to sexual intercourse without consent, sexual assault, aggravated assault, and one count of criminal endangerment, all felonies.

The Flathead County Attorney's Office added another charge earlier this month, accusing Nickerson of assault on a minor.

He has pleaded not guilty to that allegation as well.

Nickerson's attorney, Noel Larrivee of the state public defender's office, moved to dismiss the additional charge and objected to its filing.

Nickerson, who is being held on $250,000 bail, has maintained his innocence since his initial appearance more than a year ago.

According to investigators, the boy, 9 months old at the time, was admitted to Kalispell Regional Medical Center about 10 a.m. Aug. 9, 2008, with bruises on his head, a bloody mouth and other injuries consistent with sexual abuse.

Doctors at the hospital told detectives the boy, who later was flown to Sacred Heart Hospital in Spokane, had suffered traumatic brain injuries and respiratory failure.

Nickerson was arrested later Aug. 9, 2008 after driving the injured child and the child's mother from his Wildebeest Lane cabin to Kalispell Regional Medical Center.

Medical personnel notified Flathead County Sheriff's deputies of the suspected abuse after observing the child's injuries.

The child's mother told investigators Nickerson had been watching the child so she could sleep in.

Only Nickerson, the mother and her child were present in the home when the assault allegedly occurred, and the mother told detectives her son had been fine at bedtime the night before, according to detectives.

If convicted of all charges, Nickerson could be sentenced to more than 200 years in prison and fined $200,000.

Nickerson, who has been incarcerated since his arrest, also is facing unrelated assault charges for two separate alleged altercations with detention officers at the Flathead County jail.

In January 2009, he allegedly pushed a detention officer and then charged the door of his cell when officers tried to put him inside, punching one officer several times in the torso.

In April 2009, he allegedly advanced aggressively on another detention officer, who deployed his Taser.

Nickerson has pleaded not guilty to assault on a peace officer and attempted assault on peace officer, both felonies, and is awaiting trial on those charges.

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