Ada County prosecutors will ask a judge to send Cody Olson to prison for up to 20 years for the crash that also injured Olson and two others.

Olson had been smoking marijuana and drinking alcohol before losing control of a 2002 Lexus sedan and smashing into a concrete wall at the Curtis Road exit ramp March 3.

The force of the impact immediately killed backseat passenger Scott R. Hyde, 18; backseat passenger Kelsey Belcher, 18, died a week later.

Olson, 20, will be sentenced Jan. 3 by 4th District Judge Lynn Norton.

When asked by Norton Thursday why he was pleading guilty to two counts of vehicular manslaughter, Olson’s explanation was simple: “I’m guilty (of) the crime.”

Prosecutors will recommend that Olson can’t ask for parole until he serves at least five years. They also will ask for a 10-year driving ban for Olson after he is released.

Defense attorney Mark Manweiler can ask for a lesser sentence for Olson, but did not say in court Thursday if he intended to do that.

OTHER INJURIES

Olson and 19-year-old Nick Hendriksen suffered traumatic brain injuries, broken bones and other injuries, and were hospitalized for months. Jasmine Ondrick, Olson’s girlfriend who was then 17, was the only one wearing a seatbelt. She suffered a collapsed lung and broken bones and spent two weeks in the hospital.

An Idaho Vehicle Collision Report filed with the Idaho Transportation Department said a blood test showed that Olson was under the influence of marijuana and had a .07 blood alcohol content about an hour after the crash. The legal limit is .08, but according to Idaho law, someone younger than 21 with a BAC above .02 can be charged with a DUI.

Idaho court records show that Olson’s driver’s license was suspended at the time of the crash because of previous traffic citations. He received four citations — including two speeding tickets — between October 2011 and March 2012, according to court records.

Ada County prosecutors dropped two counts of felony aggravated DUI and a misdemeanor count of driving without a valid license as part of a plea agreement.

VICTIM STATEMENTS

The Jan. 3 hearing is expected to take several hours and feature victim-impact statements from the parents of Belcher and Hyde.

Prosecutors also want to allow the parents of Ondrick and Hendriksen to give statements, but Manweiler is opposing that request. He argues that Ondrick and Hendriksen are over 18, and they — not their parents — can decide to offer impact statements if they choose. A hearing on that issue is set for late November.

OTHER LEGAL TROUBLE

Olson said little during the plea hearing Thursday, answering Norton’s questions with “yes, ma’am” or “no, ma’am.” Norton said Olson recently was diagnosed with a mental health issue but did not say what it was.

Olson will get mental health and substance abuse evaluations before the January sentencing.

Olson got into more legal trouble after the crash during the months it was under investigation.

According to court records obtained by the Idaho Statesman, Olson told Meridian police in June that he was still smoking marijuana and drinking alcohol. He told friends that he had gotten a new car he was “souping up,” even though he hasn’t had a valid license since at least January; and he didn’t show up for a court hearing after being cited in June for being at a residence where drugs were sold.

Patrick Orr: 377-6219, Twitter: @IDS_Orr