Meyer was paralyzed prior to the 2002 crash, Boone said after the hearing. Boone said he convicted Meyer on a drug charge earlier in 2002, and he was in a wheelchair then.
Because Meyer cannot remember the events, Meyer's only plea option was a no-contest plea, said Meyer's lawyers, Lewis Metzner and Joshua Treem.
Under a no-contest plea, a defendant does not admit guilt, but is stating he will offer no defense.
A two-day trial had been scheduled in Meyer's case, but lawyers said during the hearing they worked out a plea agreement last week.
In exchange for the plea, the Washington County State's Attorney's Office agreed not to prosecute him on charges of reckless driving, negligent driving, speeding and illegal passing.
Assistant Washington County State's Attorney Joseph Michael said that as part of the agreement, prosecutors would not seek more than 10 years in prison for Meyer, but Meyer's attorneys will be able to argue for less prison time at sentencing.
Michael read in court the police version of what happened on the day of the crash.
Meyer was driving a BMW 330 when two men riding together saw the car turn out of Robinwood Drive and make a turn onto eastbound Mount Aetna Road.
James Spickler and Ryan Gladhill later told police that the BMW tailgated them on Mount Aetna Road, then dropped back, and near the Black Rock Golf Course "sped up dramatically," Michael said.
The BMW passed "at highway speed" and when it was about 100 yards in front of them, still in the oncoming traffic lane, the men saw the BMW crash head-on into a Ford Ranger pickup truck carrying the Dietrichs, Michael said.
Mary Ellen Dietrich was pronounced dead at the scene, and Gerald Dietrich was pronounced dead at Washington County Hospital, Michael said.
Investigators concluded that Meyer was traveling no less than 75 mph in a posted 35 mph zone, he said.
About a dozen members of the Dietrichs' family were in the courtroom, some wearing pins bearing a picture of the couple and reading, "We miss you. ... Let justice be served."
"I think it's about time he's held accountable for everything," Shirley Rogers, Gerald Dietrich's sister, said after the hearing.
Frank Meyer, Matthew Meyer's father, said after the hearing that "our heart goes out to the victims' family. ... Matthew's serving a life sentence in a wheelchair. I think enough's enough."
Meyer was released on an unsecured bond of $100,000. He will be under court-ordered supervision until his sentencing date, which was not scheduled Wednesday.