CALDWELL -- A Caldwell couple is facing felony charges after investigators say the man molested four of his children, while his wife kept silent about the abuse for nearly two decades.

Lester Kester, 48, and Sarah Kester, 50, insisted to Canyon County Sheriff's Office detectives that "a demon" had entered Lester and caused him to repeatedly sexually assault the girls.

Detectives say they found evidence that Lester had sexually abused all four of his daughters over the course of at least 16 years, beginning in 2000.

The investigation began after the Idaho Department of Health and Welfare's Children and Family Services contacted the sheriff's office June 21, informing detectives that one of the couple's daughters had come forward, telling authorities she had been molested by her father as a child.

During follow-up interviews, two of Kester's daughters told investigators they had been sexually abused by Lester, and reported that a third daughter had been as well.

The abuse continued until each girl was about 12 years old, the victims said. As the investigation continued, according to the sheriff's office, detectives found evidence that a fourth daughter had also been sexually abused, as recently as 2016.

The sisters told detectives that they had confronted their mother, Sarah, about the abuse three years ago, but nothing happened.

In an interview with investigators, according to the sheriff's office, Sarah Kester admitted she had known about the sexual abuse for 17 years, but did not report it because it was against her belief system to involve agencies like law enforcement, child protection services, or counseling services into her family matters.

Instead, she said, she prayed for "the demon" to leave her husband and tried to distract him with other tasks.

In a separate interview, Lester Kester also blamed a "bad guy" or a "demon" for his actions, according to the sheriff's office, and admitted to molesting all four of his daughters until they reached the ages of ten or 12.

Both Kesters were arrested and booked into the Canyon County Jail. Lester Kester is charged with four felony counts of lewd conduct with a minor, while his wife faces one charge of injury to a child.

Both are due in court July 26.