A Missouri man who killed his neighbor after demanding that he “turn the bass down” in his apartment was sentenced to 24 years in prison.

James C. Blanton, 29, of Maryland Heights, was sentenced Wednesday after pleaded guilty to second-degree murder, armed criminal action and unlawful use of a weapon in the death of Yi-Ping “Peter” Chang in December 2015, the St. Louis Post-Dispatch reports.

Blanton — who suffers from autism but was ruled competent to stand trial — admitted killing Chang, 35, after investigators said he told Chang to “turn the bass down” while his neighbor at the Benningtown Heights apartment complex had been watching a movie with his girlfriend, police said at the time.

Investigators were not able to determine if the loud noise actually prompted the shooting. Blanton told cops who found him outside Chang’s apartment that he shot the man in self-defense. The victim’s girlfriend was not hurt.

Prior to the shooting, during which Blanton wore a bullet-resistant vest beneath a hooded sweatshirt, he visited websites pertaining to stand your ground laws, including a news article titled, “Man cites stand your ground law after shooting neighbor over loud noise,” police said.

Several of Blanton’s neighbors, meanwhile, told the Post-Dispatch they believed he suffered from mental illness due to an apparent hypersensitivity to noise. Blanton got particularly bothered when neighbors shut their doors, leading him to slam his own door in protest, according to the neighbors, some of whom complained to building management about his behavior.

An attorney for Blanton, who did not have a concealed-carry permit for a firearm, declined to comment, according to the newspaper.