Details of Disappearance
Kantonen was last seen at Arnold Aggas Sr.'s residence in Hornbrook, California on March 8, 1989. She has never been heard from again.
She was dating Aggas's son at the time of her disappearance, and they lived together in a trailer on Aggas's property. Her boyfriend was involved with someone else, however, and had invited the other woman to share the trailer. Kantonen had to sleep on the couch and was very unhappy about it.
The last time she saw her mother, Kantonen said her boyfriend's father had a bad temper and had made unwanted sexual advances. After Aggas found out Kantonen was pregnant, he was reportedly angry and prevented her from seeking prenatal care. Her mother tried to convince her to move out, but Kantonen wanted to marry Aggas's son.
It was Aggas who reported Kantonen missing. He presented a four-page letter, which he said Kantonen had left by his son's bedside. The letter said Kantonen had met a truck driver and was moving to Washington State with him and would raise her baby on her own. Although the letter appeared to be in her daughter's handwriting, Kantonen's mother doesn't believe she would have moved to another state without telling her, or cut her baby's father out of its life.
Kantonen's mother thought foul play was involved in her daughter's disappearance and began circulating missing persons fliers for her and discussing her case with law enforcement. She then began receiving anonymous calls telling her to stop talking to the police, or she would end up like Kantonen.
In June 2011, Aggas was arrested for sex crimes committed in 2007. When the authorities searched his residence, they found unspecified evidence that lead them to charge him with murdering Kantonen.
A photo of Aggas is posted with this case summary. In April 2014, he pleaded no contest to two counts of involuntary manslaughter, one count for Kantonen and one for her unborn child, and one count of preventing a witness from testifying. He was sentenced to thirteen years in prison, but with credit for time served and work credits he gained in the prison system, he was able to shorten his sentence and was released in February 2019.
Foul play is suspected in Kantonen's case due to the circumstances involved.