Trevor B. Atchison, 21, of Alpha, Ill., who police say was shot in the head by his wife, was taken off life support Thursday and pronounced dead.

An autopsy was scheduled for Thursday afternoon in Peoria, according to the Henry County Sheriff's Department.

Additional charges are pending against Atchison's wife, Robin Carr Atchison, 29, of Alpha, Ill.

Charges have been filed against Atchison, accusing her of shooting her husband in the head early Tuesday. Authorities also have arrested a man they say illegally sold her the gun used in the shooting.

Trevor Atchison, 21, had been listed in critical condition Wednesday, one day after being shot by his wife with a .22-caliber rifle she allegedly purchased illegally from a Woodhull man, Henry County Sheriff Jim Padilla said.

Robin Atchison, as of Wednesday, is charged in Henry County Circuit Court with one count of reckless discharge of a firearm, a Class 3 felony under Illinois law that carries a prison sentence of two to five years. She also is charged with one count of being a felon in possession of a firearm, a Class 4 felony that carries a prison sentence of one to three years.

She was being held Wednesday night in the Henry County Jail on $500,000 bond.

More serious charges could be added after his death and as the investigation continues, authorities said.

According to Scott County Iowa District Court records, Robin Atchison pleaded guilty to a charge of second-degree theft in 2005. Her last name then was Carr. The charge is a Class D felony under Iowa law. She was sentenced to a three-year term on probation that she completed and paid restitution, fines and court costs of $2,709.09. The felony conviction precludes her from possessing a firearm.

Clint David Cole, 23, was arrested Wednesday and charged with one count of unlawful sale of a firearm to a felon. The charge is a Class 3 felony under Illinois law.

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Cole was released from the Henry County Jail after posting 10 percent of a $50,000 bond.

Cole has a minimal criminal history that includes convictions in Henry County Circuit Court for being a minor in possession of alcohol, driving under the influence of alcohol and traffic violations.

Henry County sheriff’s deputies responded to a 911 call for a shooting at 504 S. 1st St., Alpha, at 3:45 a.m. Tuesday. They found that Trevor Atchison had suffered a single gunshot wound to the head.

They took Robin Atchison into custody Tuesday morning.

The investigation is being conducted by the Henry County Sheriff’s Department.