JACKSONVILLE, Fla. -

The man accused of killing 17-year-old Jordan Davis during an argument over loud music will face a second murder trial in September, a judge ruled on Monday.

Dunn was convicted in February of attempting to shoot and kill three teenagers in a vehicle with Davis but the jury was unable to reach a conviction on the first-degree murder charge in Davis' death.

Judge Russell Healey said jury selection for the retrial would begin Sept. 22 and continue through the following week until a jury of 12 plus four alternates is seated.

Sentencing on the existing convictions on three counts of attempted murder and one count of shooting into an occupied vehicle was postponed until after the murder retrial.  Healey granted the delay at the request of the defense, which said if Dunn took the stand at his sentencing hearing to address the court or Davis' family, what he says could be used against him in his murder trial.

Dunn faces a minimum mandatory sentence of 60 years for the four convictions related to the shooting.  On Monday', Healey said he would not change his mind on the sentencing delay.

"While I could do it legally, it concerns me that it could open up other matters on appeal," Healey said in court.

Jordan's parents say they have not given up on justice for their son, and they are determined to get a murder conviction for their son's death. They have been at every single court hearing since he was killed in November 2012.

"I want him to also be tried and said by the courts in the state of Florida that you were wrong for killing Jordan Davis. And if that doesn't happen I will not, nor will I ever be satisfied," said Jordan's father, Ron Davis.

"So we are moving at a snails pace," said Jordan's mother, Lucia McBath. "That's the way we feel about it, but we know that that is the system, that is the process. We have been very patient, but we are looking forward now to actually moving forward and getting some closure for Jordan and for our families."

Dunn will have a new attorney for the appeal: Waffa Hanania.  She has not comment on the case, which is common for lawyers in pending legal cases.