Even after Mackenzie Glade Hunter completed his 15-month prison term this fall for illegally selling a gun to the Trolley Square shooter, the parents of a woman who died in the rampage hoped to make him serve more time.

On Tuesday, though, the 10th U.S. Circuit Court of Appeals threw out a request that would have reopened the case and forced a resentencing.

The Denver-based court dismissed an appeal by Sue and Ken Antrobus asking that they be declared victims of the unlawful gun sale under the federal Crime Victims' Rights Act (CVRA). That designation would have given them the right to ask for stiffer punishment at a new sentencing hearing before U.S. District Judge Dale Kimball in Salt Lake City.

The couple want Hunter to serve 99 months behind bars for selling a handgun to Sulejman Talovic, who used the weapon to kill their daughter, Vanessa Quinn. Instead, Kimball imposed a 15-month term after ruling that the Antrobuses could not speak at the sentencing because Quinn was a victim of the shooting itself, not the gun sale.

The Antrobuses turned to the 10th Circuit, which declined to order Kimball to allow them to speak at the sentencing and turned down a second appeal in March.

Hunter, now 21, was sentenced in January and released from prison in September. He was given credit for the five months he spent in jail before his sentencing and also got about two months off for good behavior.

In Tuesday's decision, the 10th Circuit said a successful appeal would "produce the extraordinary result" of requiring a new sentencing hearing for Hunter, who struck a plea bargain with the government. The court said prosecutors determined what they believed to be the proper sentence, and the law shows Congress did not intend non-parties to be able to change those decisions.

U.S. Attorney for Utah Brett Tolman said his office, which had argued the Antrobuses had no right to request that Hunter be resentenced, is satisfied with the ruling. Despite the fact that Quinn and her parents are not considered victims under the CVRA, his office "has extended every courtesy to the Antrobuses and the other families that were affected by the tragic events at Trolley Square," he said.

Scott K. Wilson, a federal public defender who represents Hunter, declined comment.

Talovic had purchased the Smith & Wesson from Hunter eight months before the massacre, when he was too young to buy the handgun legally.

Attorney Paul Cassell, who represents the Antrobuses, said he is disappointed with the decision but sees a silver lining: The 10th Circuit said the couple can ask Kimball for another hearing on their request for a resentencing based on what they allege is newly discovered evidence. That evidence is a report by the Bureau of Alcohol, Tobacco, Firearms and Explosives in an interview with Hunter, who purportedly recounted a conversation in which Talovic said he wanted a gun to rob a bank. The Antrobuses say the alleged comments show Hunter was put on notice that the firearm would be used in a violent crime and makes them victims.

The government has argued that even if Talovic had mentioned a bank robbery, the shootings were not foreseeable because of the eight-month lapse between the gun sale and the massacre. The U.S. Attorney's Office has declined to give the AFT report to the Antrobuses, saying the federal Privacy Act bars its release unless Hunter gives written consent.

pmanson@sltrib.com