Levi Axtell, 27, allegedly beat Lawrence Scully, 77, more than a dozen times with a shovel – before he “finished” him off with the large pair of antlers – at the older man’s home in Grand Marias.
Just minutes after the brutal crime, Mr Axtell turned himself in to authorities, walking into Cook County Sheriff’s Office covered in the victim’s blood and confessing to killing him.
He was arrested and charged with second-degree murder.
The Cook County Sheriff’s Office said that Scully was found dead inside his home in Grand Marias on Wednesday.
A witness told investigators that they saw a person in a white Dodge Caravan pulling into the driveway of the victim’s home at around 5pm, according to the criminal complaint.
The driver allegedly got out and smashed a vehicle in the driveway before running inside the home.
The witness said they then heard screams coming from inside the property, before the driver emerged again and fled the scene.
The driver – later identified as Mr Axtell – drove straight to the police station where he fell to the floor with his hands on his head and urged officers to put handcuffs on him before he hurt someone else, according to the complaint.
Officers responded to Scully’s home to find his body lying next to a bloody shovel.
A preliminary autopsy found that he died from blunt force head injuries and that he had defensive wounds on his arms.
Mr Axtell told investigators that he had found a shovel on the deck of the elderly man’s home and used it to strike him over the head about 20 times, according to the criminal complaint.
He then “finished him off” by hitting him several more times with the antlers.
Mr Axtell told investigators he “believed him to have sexually offended against children in the past”.
Scully, who ran unsuccessfully for mayor in 2014, was convicted of sexually assaulting a six-year-old girl back in 1979.
He and Mr Axtell had a long history of conflict, culminating in the 27-year-old taking out a protective order against the 77-year-old a few years back.
Back in 2018, Mr Axtell had accused Scully of “stalking” and “attempting to groom” his 22-month-old daughter, claiming that he had seen him parked outside of her daycare centre, according to court filings obtained by WTIP.
Mr Axtell sought a protective order against Scully on behalf of his daughter.
The order was initially granted but was then dismissed weeks later.
Mr Axtell is now being held behind bars in Cook County Jail on $1m bail.
He is scheduled to next appear in court on murder charges on 10 April.