Bernalillo County deputies are still trying to piece together how 56-year-old Katherine Cullen ended up driving the wrong way on Interstate 40 near Tijeras, hitting 56-year-old Judith Bjorkman of Edgewood head on in a collision that killed both women late last Wednesday.

Bernalillo County Sheriff's Lt. David Knowles said this week that alcohol and drugs don't appear to be a factor in the crash.

A 2-year-old was in Bjorkman's Ford Expedition but wasn't badly injured in the crash. He was treated at University of New Mexico Hospital and released to his family on Thanksgiving, Knowles said.

The toddler was properly strapped into his seat in the back of the car but was still lucky to make it out of a particularly destructive crash, Knowles said.

Bjorkman's husband of 35 years, Ty Bjorkman, told KOAT-TV that Bjorkman regularly baby-sat the 2-year-old for friends.

"She's got two kids and two grandkids that are going to miss her even worse than I do," he told KOAT-TV. "She always had a smile on her face. Every time she left the house to go somewhere she said, 'I'll be right back.' This time she wasn't.

"She didn't deserve this. This should not have happened to anybody, let alone her," Ty Bjorkman said.

Cullen, who is from Santa Fe, was driving a Jeep Cherokee eastbound in the westbound lanes about 8 p.m. Nov. 25 when the crash occurred about a quarter mile west of the Tijeras exit, Knowles said.

Knowles said that several people had called 911 to report the vehicle driving the wrong way.

He said it is unknown how Cullen got on the wrong side of the freeway.

"Right now, we don't know where she got on the interstate — whether it was at the Carnuel or Tramway exits," Knowles said.

Deputies, he said, are busy reconstructing the circumstances leading to the crash.

"This is more than just a run-of-the-mill traffic investigation," he said.

Knowles said he could not give an indication of when the investigation might be done.

According to crash data collected by the state, there is a fatal crash about four times a year on I-40 between Moriarty and Albuquerque, primarily in Tijeras Canyon.

In October, a semi crashed into the hillside on I-40 near the Carnuel exit, killing the driver, Charles Wayne Scalf, 61. He was heading west when he drove off the road and crashed, trapping him inside the cab.

In September 2008, Larry Jaramillo died when a minivan swerved to avoid a mattress. The vehicle Jaramillo was riding in with his mother smashed into the back of the van.

Telegraph editor Rory McClannahan contributed to this report.