A 47-year-old software developer was convicted Saturday of attempted murder for shooting into a carful of teenagers after an argument over what he called their “thug music,” but jurors couldn’t agree on the most serious charge of first-degree murder.

After more than 30 hours of jury deliberations over four days, a mistrial was declared on the murder charge that Michael Dunn faced in the fatal shooting of one of the black teens. The 12 jurors found him guilty of three counts of attempted second-degree murder and a count of firing into an occupied car.

Dunn was charged with fatally shooting 17-year-old Jordan Davis, of  Marietta ,  Ga. , in 2012 after the argument over loud music coming from the SUV occupied by Davis and three friends outside a  Jacksonville  convenience store. Dunn, who is white, had described the music to his fiancee as “thug music.”

Dunn showed no emotion as the verdicts were read. Each attempted second-degree murder charge carries a maximum sentence of 30 years in prison, while the fourth charge he was convicted on carries a maximum of 15. A sentencing date will be set at a hearing next month.