Attorneys are painting two very different pictures of a woman who was behind the wheel of an SUV that slammed into a pickup truck, killing a Thornton family of five.

Investigators say Monica Chavez suffered a seizure just before the collision at 84th Avenue and Grant Street.

They say her southbound SUV hit the median and went airborne before striking two vehicles, one of them belonging to Randy and Crystaldawn Stollsteimer.

The impact killed the couple and their three children, Sebastian, Darian and Cyrus.

In her opening statement on Tuesday, Deputy District Attorney Tiffany Sorice told jurors about a doctor’s admonition to Chavez following a previous seizure in 2006.

“You are instructed to see a neurologist within five days. You are also instructed not to drive until cleared by a neurologist,” said Sorice. “Because the defendant, Monica Chavez, ignored those instructions, a family of five was killed on February 17, 2011.

But defense attorney Megan Downing said that wasn’t the case.

“She committed no crime,” Downing said. “She (Chavez) did nothing unlawful. She did nothing unreasonable and she did nothing negligent.

Downing said doctors weren’t sure if Chavez had indeed suffered a seizure or if it was just a fainting spell.

She said the collision was just a tragic accident, “that no one could have predicted.”

A total of 16 witnesses testified on Tuesday.

Two of them said they noticed the driver of a white SUV driving south on Grant street.

Both saw the driver’s head bobbing or jerking back and forth and interpreted it differently.

“It looked like she was having a seizure,” said Veronica Espinoza.

“The only thing that came to my head was that (she) was rolling down the window,” said Josephine Martinez while imitating the movement of a manually operated window crank.

Another witness said she noticed the SUV picking up speed, and then later saw debris flying.

Prosecutors asked the defendant’s husband, George, about two previous seizures, one at an Albertson’s store in February 2006, and one at a McDonalds in August 2010.

George Chavez said the 2010 episode didn’t raise a red flag, because he thought she just blacked out after suffering from heat stroke.

He said he didn’t link the 2006 incident to what happened last year because it was so remote in time.

Chavez’ daughter, Serriah, and son, George Jr., were with her when the accident happened.

Serriah tearfully told jurors that they were at a red light when “She (mom) started to shake. She was telling me that she couldn’t breathe.”

She said her mom’s foot got stuck on the pedal and they started to move. She said the car stopped, “when we landed.”

Chavez’ niece, Jolene Vasquez, told the court that she was with Monica during the first incident in 2006, and that it scared her.

The prosecutor asked Vasquez if Chavez remembered what happened immediately afterward. The niece responded, “No.”

The prosecutor asked, “What did you tell her?’

Vasquez replied, “I just told her that she started shaking and that she fell down and hit her head. I called for help.”

The prosecutor asked, “Did you tell her she had a seizure?

Vasquez replied, “Yeah, I think I told her that. That’s what I called it. I don’t know.”

Vasquez said she didn’t remember a doctor instructing her aunt to see a neurologist and to refrain from driving until she did so.

Under questioning by the prosecution, Vasquez did admit that she didn’t want to hurt her aunt.

Trooper Trent Waters of the Colorado State Patrol, showed jurors an animated video of what investigator believe happened.

It shows the SUV hitting the median and going airborne before hitting a Mazda and the Stollsteimer’s Chevy S-10.

Waters estimated that Chavez was driving 74 mph when she struck the Mazda and 68 mph when she hit the Chevy.

She's been charged with five counts of negligent homicide and two counts of child abuse.

The prosecution is expected to wrap up its case early tomorrow. The defense will likely finish later in the day or on Thursday.