Amber Frey, who testified against Peterson during his 2004 trial, bought a house in Clovis in 2005, taking out a $431,000 mortgage, the Fresno Bee reports. Court records show that in May she owed $16,000 in overdue payments.
A notice of default was issued on Sept. 4 and an auction is scheduled next week. If the house is sold at auction, Frey could be forced out almost immediately, but banks have become more open to negotiating with homeowners because of the sharp drop in prices.
Frey, a massage therapist, opened a day spa in Clovis last year.
Frey has said that she did not realize Peterson was married when she began dating him but eventually became suspicious of him and asked a police officer friend to check him out. She later taped conversations with Peterson to assist in the investigation.
Peterson is now on death row in California.
2014: The Year in Music [PHOTOS]