The attorney for an Apple Valley woman charged in a triple vehicular homicide argued on Friday that the case has been "prejudiced" against her because authorities destroyed her wrecked car -- and the "black box" in it.

Attorney Bill Sherry said defense experts could have determined from information inside that black box how fast Brittany Mertz was driving and whether she braked just before the 2008 collision that killed an adult and two children and injured two others in Inver Grove Heights.

Mertz, 21, formerly Brittany Krueger, is charged with three counts of criminal vehicular homicide, two counts of criminal vehicular operation, careless driving and reckless driving.

"I feel it was an accident. Yes, I do," Mertz said softly after the hearing in Dakota County court, in which Sherry contested the state's evidence.

Authorities allege that as Mertz was driving on Hwy. 52 on April 17, 2008, she looked down briefly at a photo and her car drifted into another lane. Mertz's passenger allegedly yanked the steering wheel.

That's when the car went out of control, crossed a grassy median and caused a head-on collision that killed Brittany Carlson, 30, of Zumbrota, Minn. Her 2-year-old son, Brandon Dion-Faris Carlson, died two weeks after the accident, and Tamaya Phillips, 4, of Rosemount, died the day after the collision. Two other children in the Carlson car survived.

A criminal complaint says Mertz admitted that when her car hit the median, she took her hands off the wheel and covered her face. At issue is whether she was grossly negligent. The complaint says an accident reconstruction found that there was no steering or braking of Mertz's car once it hit the median.

Darrell Carlson of Wabasha attended Friday's hearing in Hastings, calling it one more step in a long process toward closure in the deaths of his daughter and grandson. "I saw the accident scene, and to me it's irrelevant," Carlson said about the missing black box.

Mertz's friends have rallied behind her. "She's not a horrible person," said Denise Grace, 56, of Burnsville. "She feels bad for the loss of life. She's a mother herself."

Joy Powell • 952-882-9017