By Paul Walsh and PAT PHEIFER  Star Tribune staff writers

A 17-year-old boy has been charged with driving his new car nearly 100 miles per hour in a swerving thrill ride that went unexpectedly airborne along an interstate frontage road in Burnsville, pitching two of his four teenage passengers to their deaths.

Joshua L. Decoteau of Burnsville was charged Wednesday in Dakota County's juvenile court with a host of counts in connection with the deaths last summer of Frederick J. Alexander, 16, of Burnsville, and Alesha K. Roehl, 17, of rural Northfield.

The crash occurred about 2:30 p.m. on Aug. 21, 2012, when the 1992 Toyota Camry veered off Buck Hill Road, left a half-block of skid marks, went through a security fence and rolled down a grassy embankment onto the shoulder of Interstate 35.

Decoteau, who was slightly hurt, had violated a state law limiting how many teenage passengers could ride in his car, according to the State Patrol. The teen had received his license less than six months before the crash, during which time the law allows only one passenger under age 20.

County Attorney Jim Backstrom said Decoteau had been driving the car for just five days before the crash.

"This case appears to be an example of how quickly an inexperienced driver can lose control of a vehicle if speeding and driving recklessly," Backstrom said.

None of the three back seat passengers, including Alexander and Roehl, were wearing seat belts, Backstrom added.

Alesha Roehl's grandmother, Cindy Roehl, said the family didn't know about the charges against Decoteau until they were contacted by a reporter Wednesday. They have some sympathy for the teen.

"We've kind of said all along — he's a kid, he screwed up badly. How many of us haven't?" she said. "No matter how he gets punished, it won't bring our kids back. He probably has the worst end of the deal. He has to live with this the rest of his life."

Alexander and Roehl went to Lakeville South High School's alternative learning center. The others went to Lakeville South.

Roehl would have graduated with her classmates this year. Cindy Roehl said she and her family went to commencement exercises, where there was a picture of Alesha on stage and her name was announced.

"We miss our girl something terrible," her grandmother said.

The charges against Decoteau are: two felony counts of criminal vehicular homicide (involving gross negligence) and one felony count and one gross-misdemeanor count of criminal vehicular operation (involving gross negligence resulting in substantial bodily harm).

The case is being filed under the state's Extended Juvenile Jurisdiction statute. The statute calls for a stayed adult prison sentence and extension of the juvenile court's jurisdiction over the case until the defendant turns 21 years old.

It's not unusual for a case like this to take months to charge. If convicted, Decoteau would have to comply with all conditions set by the court, which could include detention in a juvenile facility, community work service, educational or community speaking and attendance at MADD panels. If he did not comply, he could receive the full adult sentence, typically four years for criminal vehicular homicide.

Backstrom said it's rare for his office to certify a juvenile to stand trial as an adult for a crime that isn't intentional.

"While this was a serious crime, it didn't involve any intent on the part of the driver to kill anyone," he said.

paul.walsh@startribune.com 612-673-4482 pat.pheifer@startribune.com 952-746-3284