Details of Disappearance Catherine was last seen in Hot Springs, South Dakota between 6:00 and 7:00 a.m. on October 5, 2011. She was carrying $10,000 in cash at the time of her disappearance and intended to purchase a motor home. She had already placed a $1,000 down payment. She never showed up to buy the motor home and has never been heard from again.
It's uncharacteristic of Catherine to leave without warning, and her daughter stated she would never have left because she was taking care of her elderly father. The contents of her purse were found dumped on a gravel road northeast of Buffalo Gap.
In July 2012, Catherine's son, Matthew Charles Tornquist, was charged with murder and grand theft in connection with his mother's disappearance. He'd been in federal custody for weapons offenses since earlier that year; authorities had found stolen guns in his college dormitory room.
A photo of Matthew is posted with this case summary. At his trial in the summer of 2014, the prosecution alleged he shot Catherine to death in her bed with a stolen .22 caliber rifle, dragged her body outside her home, put it in his car, disposed of it, and spent the money she'd intended to buy the motor home with.
Although someone had cleaned up the bedroom, traces of Catherine's blood were found on her bed and there was a trail of blood leading outside. There were two spent bullets in Catherine's mattress and another in the trunk of Matthew's car; they all had hair consistent with Catherine's stuck to them. There was a bloodstained sheet of plywood on Catherine's property and a partially burned cellular phone in the burn barrel.
One of the stolen guns found in Matthew's dormitory room, a .22 caliber rifle, had skin cells on it that matched Catherine's DNA, and her blood was found on a pair of his jeans. In addition, Matthew gave multiple stories to people about his mother's disappearance, and the alibi he provided turned out to be fictitious.
The jury deliberated only two hours before convicting Matthew of murder, although he maintained his innocence. He was sentenced to life in prison without parole.
Catherine's body has never been found, but foul play is suspected in her case due to the circumstances involved.
- South Dakota Division of Criminal Investigation
Updated 2 times since October 12, 2004. Last updated December 13, 2018; picture added.