GRAND RAPIDS, MI - A man who attacked a tribal police officer, stabbing at the officer's face with a pen as they grappled on the ground, is overwhelmed with guilt, he said.

"I understand the seriousness of the situation and the impact it has had on others and I am sincerely sorry," Aaron Vorac, wrote in a letter to U.S. District Judge Robert Jonker in Grand Rapids.

"This is not a demonstration of who I am."

Assistant U.S. Attorney Jeff Davis said Vorac, who will be sentenced Friday, Dec. 1, deserves the maximum penalty under sentencing guidelines - seven years, three months - for the violent attack of Officer George Closser, who suffered a concussion and gashes on his head.

He said Vorac's "continued minimization and attempted rationalization" should be taken into account at sentencing.

The trouble started around 4:30 p.m. Jan. 15 at Odawa Casino Resort in Petoskey, after Vorac, 37, and his wife, Carla Weiskopf, were refused re-entry after she allegedly urinated on herself near the craps table, the FBI said.

The couple twice tried to re-enter before police were called by security.

When Closser, an officer for the Little Traverse Band of Odawa Indians, responded to the scene, he asked the couple for identification. Vorac told the officer that "he was a military member and just wanted to leave and that there was going to be a problem if he was going to be arrested for something he did not do," Davis wrote in a sentencing memorandum.

He said Vorac got out of his vehicle and advanced on the officer, who grabbed one of Vorac's hands while reaching for his baton. Weiskopf, he said, stepped between the men and grabbed the officer's arm.

The two men wrestled to the ground before Vorac got on top of the officer and repeatedly punched him in the groin, Davis said.

Vorac then said he was going to stab the officer with a pen from the officer's shirt pocket, the prosecutor said.

"As he was making this statement, the videotape shows the Defendant grabbing the officer's pen and violently slashing at the officer's eyes. Had the Defendant been sure in his aim, this Officer would have likely lost one or both eyes," Davis wrote.

"Two security guards attempted to intervene, but the Defendant was able to free his right arm and took multiple stabs at Officer Closser's eyes, face and head," he wrote.

He said Closser suffered a concussion and had open gashes on his forehead.

Davis said that Vorac, who pleaded guilty to forcible assault on a federal officer, has blamed Closser.

Vorac told a probation officer, conducting a pre-sentence investigation, that Closser "drew a weapon and took a position to strike. 'Way over the top and out of line. The officer did not act as an officer of the federal level or of any real level for that matter,'" court records showed.

Defense attorney Matthew Borgula, a former federal prosecutor, argued that the officer's pen did not qualify as a dangerous weapon.

If not for that designation, Vorac's sentencing guidelines, which are advisory, would be 12 to 18 months in prison. Instead, guidelines call for a minimum ranging from 70 to 87 months.

"The question for this Court is whether when Mr. Vorac found what appeared to be Officer Closser's pen in his hand during the fight whether it was used in a way that transformed it from an ordinary object into a dangerous weapon," Borgula wrote in court documents.

"Certainly, Mr. Vorac could have grabbed Officer's blackjack or his firearm. He did not, and the injuries sustained by Officer Closser appear to be an abrasion on his forehead, likely caused by the scuffle on the rough pavement."

He said his client doesn't deserve decades in prison.

He said sentencing guidelines involving federal officers "make no distinction between Mr. Vorac's fight with a man that he thought was a casino security guard, and for example, a cartel member that fires as an undercover DEA agent with an assault rifle (and misses)," he said.

If he had faced state charges, he would have been looking at nine months in jail, at most, his attorney said.

Vorac's family and friends said the incident was out of character for him. He just got a good job, and a glowing letter to the judge from his boss.

An assault on an officer is not the example he wants to set for his children. He and his wife have six between them.

He's the family's sole provider. His wife pleaded guilty to state charges for resisting police and lost her job.

Other than a misdemeanor 20 years ago, Vorac hasn't been in trouble. He knows he made an alcohol-fueled "terrible mistake," Borgula said.

He's been sober since.

"... (H)ad he left the casino that night and not gone back, none of us would know his name," Borgula said.

Vorac and his wife left the casino after she was cut off from alcohol and asked to leave.

They were driving away when she said she wanted to go back to complain.

She caused a scene, the defense said.