A man who lit his girlfriend on fire during an argument over karaoke could spend 15 years in prison after pleading guilty Friday to one count of felony domestic battery.

Dustin R. Hieronymus, 38, told a Coeur d’Alene judge he was responsible for the scars on his former girlfriend’s hands and face caused from dousing her with acetone and setting her on fire during a Valentine’s Day quarrel.

First District Judge Richard Christensen accepted the plea agreement to the amended charge and scheduled an Oct. 18 sentencing.

Hieronymus was originally charged with aggravated battery, third-degree arson and felony domestic battery, which carried a maximum penalty of 10 years in prison and a $10,000 fine. The complaint was amended as part of the plea agreement reached through mediation and now calls for a five- to 15-year term — and allows defense attorneys to argue for a lesser sentence.

Hieronymus pleaded guilty to dumping kerosene on his girlfriend, a 27-year-old woman, after the couple returned home from a Valentine’s Day outing at the Main Street Bar in Rathdrum.

The girlfriend was singing karaoke and did not want to leave the tavern while Hieronymus pressed her to go, according to a report. The couple argued, then returned around 7 p.m. to a residence they shared on the 14000 block of North Idaho Road, where the argument continued.

The girlfriend said Hieronymus covered her head with a metal pail and struck the pail, causing bruising of the victim’s head. Then Hieronymus doused her head and upper body with kerosene and lit the fuel.

Police said the woman suffered cuts and burns to her arms and face, and her hair was burned. Hieronymus had a bruise and cut above his left eye, where he was struck with a frying pan. He also suffered burns from trying to put out the fire.

Hieronymus told police that his girlfriend set herself on fire because she was emotional and suicidal.

“According to Hieronymus, (the victim) and him continued to argue and she suddenly set herself on fire,” according to a police report.

Hieronymus was on parole when the Valentine’s Day incident occurred. He was released from prison a year ago after being convicted of aggravated assault in 2015.