An Illinois man is accused of his mother’s brutal and premeditated murder after a fisherman found the incomplete remains of a dismembered body in a Chicago lagoon Saturday.

Though analysts have not determined the torso and two partial legs belong to 76-year-old Gail Peck, authorities said they had enough evidence to arrest her son, 55-year-old Brian Peck, in connection with her murder.

According to the Chicago Tribune, Brian Peck told police his mother took her dog for a walk and never returned when he reported her missing Friday afternoon.

While authorities initially notified the public and asked for assistance locating the missing woman, they reportedly soon grew suspicious of her son’s story.

By Saturday, police announced they were no longer asking for tips.

According to prosecutors, Brian Peck told investigators that he killed his mother early on the morning of October 25. The two had been arguing over the volume of the music he was playing, he said, claiming his mother threatened him with a knife.

He allegedly knocked his mother to the ground and stomped on her legs and neck until he realized she was dead.

From there, prosecutors say he took her body to a bathtub and used a saw to dismember it.

After a fisherman found a duffel bag containing a handsaw and body parts on Saturday, police sent divers into the lagoon. They reportedly found a suitcase with the victim’s torso inside.

The remains found Saturday include a medical scar investigators say is consistent with one resulting from a spinal fusion surgery, which Gail Peck had undergone.

Gail and Brian Peck reportedly lived together, at least occasionally, and at one point shared a home in Oak Brook. The two also had a documented history of violence, the Chicago Daily Herald reports.

Last year, Gail Peck filed a protection order against her son, whom she said threatened to kill her during a physical altercation. That argument also reportedly stemmed from the mother asking her son to turn down his music.

His previous criminal record includes a 2016 guilty plea for domestic battery causing bodily harm and another guilty plea in 2013 for aggravated battery.

A judge ruled on Tuesday that he be held without bail on charges including two counts of first-degree murder and one count of concealment of a homicidal death.

[Featured image: Elgin Police Department]