An Illinois man who stabbed his mother to death back in 2008 allegedly admitted that the murder stemmed from a fight that ensued after his mother refused to get him premium Avril Lavigne concert tickets, according to the Huffington Post.

The prosecution in the case against Robert Lyons of Carol Stream, Ill. (a suburb of Chicago) is now claiming that Lyons killed his mother, Linda Bolek, on March 14, 2008 not because he suffers from bipolar disorder, but because he grew enraged after Bolek refused to make a phone call to arrange skybox tickets for an upcoming Avril Lavigne show. Prosecutors are claiming this fight provoked Lyons, who resided with Bolek, to strike his mother over the head with a champagne bottle and stab her nine times in the back.

Lyons, 39, was arrested shortly after at a Hooter's restaurant in Schaumburg, Ill. Police found the body of Bolek after neighbors called the authorities to report a possible domestic dispute. Before he fled the scene of the crime, Lyons dumped household cleaning products over Bolek's body.

Lyons has been charged with first-degree murder. His trial began in Illinois last Wednesday.

The defense in the case is claiming that Avril Lavigne tickets are not to blame for the killing, citing Lyons' bipolar disorder as the root of his rage. According the Huffington Post, "Assistant Public Defender Valerie Pacis argued in court that Lyons' actions were reactive and unplanned." The defense is also claiming that Lyons and his mother often fought, citing an incident in which Bolek once threatened her son with a kitchen knife during a quarrel.

Conversely, Assistant State’s Attorney Ann Celine O’Hallaren stated in court on Wednesday that the evidence -- particularly the multiple stab wounds -- does not support the fact that Lyons might have been acting in self defense.