"It goes without saying this was a huge day for me," Cardon said after the brief hearing Friday. The dismissal was "unexpected, but a great surprise."
Salt Lake County District Attorney Sim Gill said Friday his office filed a motion to dismiss the charge after determining the expert testimony on which the case was based had changed.
"I can't be more specific," he said. "We couldn't prove beyond a reasonable doubt in light of the changed circumstances."
The Utah Fraternal Order of police expressed its support for Cardon in a prepared statement released Friday.
"The facts of this case do not suggest an unjustified use of force, and the government has finally got it right," said FOP general counsel Bret Rawson. "Jared is a great law enforcement officer… thank goodness this miscarriage of justice has been corrected."
The shooting happened on May 2011, after Cardon made a traffic stop near 5275 W. 3500 South. Without a shoulder on that road, traffic backed up behind him. Motorist Jose Contreras apparently couldn't stop in time. He crashed into a pole, then tried to drive away toward Cardon.
Cardon fired three shots, two at the vehicle and one at the vehicle's tire.
While Cardon said he was trying to protect himself, Gill determined the shooting was unjustified based on witnesses reports that Contreras tried to drive around Cardon, not at him, and Cardon moved toward the car as if to get a better shot.
On Friday, his attorney disputed that account.
"We have witnesses who said Jared did what he should have done," said Linsday Jarvis.
Contreras, meanwhile, pleaded guilty in February to a third-degree felony count of aggravated assault and a misdemeanor count of failing to stop at an officer's command. He was sentenced to 36 months of probation.
Cardon was found to be justified in another shooting in 2007, when he shot a man who revved his engine as though he would ram Cardon and flee in a stolen car. A jury cleared Cardon in a civil trial in October.
Cardon also has been cleared of excessive force allegations made by another man, Cesar Medina, who claimed Cardon tackled him during a traffic stop.