A man from Campton Hills, Illinois, killed his mother with a baseball bat in “self-defense” after mistaking her for an intruder, prosecutors said Tuesday.

Thomas J. Summerwill, a 21-year-old college student, was home on a spring break when the incident took place in the early morning hours of March 24. It came to light after his father called 911 and said Summerwill had hit his mother with a baseball bat after she entered his bedroom. Mary Summerwill, 53, was rushed to a nearby hospital where she succumbed to injuries a few hours later.

“Kane County prosecutors allege that the morning of March 24, 2019, Summerwill awoke to what he believed was an intruder in his bedroom. Acting in what he believed was the defense of himself or his property, Summerwill grabbed a baseball bat and struck the person multiple times in the head with the bat, not realizing the person was his mother, Mary Summerwill, who died as a result of the blunt force trauma,” the Kane County State’s Attorney’s Office said in a statement Tuesday.

The prosecutors, however, said Summerwill’s belief was “not reasonable” because he was under the influence of alcohol.

Liam Dixon, the defense attorney, said, “If they allege alcohol played a role, I don’t know if that changes his reasoning,” the Chicago Tribune reported. “It was a freak accident and a tragic, horrible story all the way around,” Dixon said, adding that Summerwill’s family supported him.

He, however, said he wasn’t sure about why the victim went to Summerwill’s bedroom.

“They had an excellent relationship. I wouldn’t even call it a typical relationship; I would say it’s very loving. She adored him,” Dixon said.

The prosecutors filed a second-degree murder charge against Summerwill who surrendered to authorities Monday after the state’s attorney’s office filed criminal charges. He appeared in court Tuesday and his bond was set at $30,000. He was scheduled to appear in court again May 23.

“The charges against Summerwill are not proof of guilt. Summerwill is presumed innocent and is entitled to a fair trial in which it is the state’s burden to prove guilt beyond a reasonable doubt,” the Attorney’s Office said in the statement.

This representative photo shows handcuffs at the Commissariat de Police Nationale (National Police Station) in Alfortville, France, Nov. 21, 2016. Thomas Samson/AFP/Getty Images