Investigators this week charged a 24-year-old York County woman with having a four-month sexual relationship with a 12-year-old Columbia boy.

The boy's mother allegedly arranged the sexual encounters between Ashley Laurie Banks and her son at the family's Columbia home, court documents say.

Banks, formerly of 562 Atlantic Ave., paid for the encounters, which occurred on a "nightly basis" from August to December 2005, according to the documents.

Banks — also known as "Gemini" or "X" — was charged with rape of a child, a first-degree felony, and corruption of minors, a first-degree misdemeanor.

If convicted, she could face up to 25 years' imprisonment, Lancaster County District Attorney Don Totaro said Thursday.

The child's mother is being investigated and could be charged as well, Columbia Borough Detective Dan Bell said.

The victim first told a counselor at Lancaster County Children and Youth agency in September about the encounters with Banks, a police affidavit states.

The boy told the counselor "he was being prostituted out by his mother," police say in the affidavit.

During an interview with police in November 2006, the boy said the encounters occurred on a "nightly basis," the affidavit says.

A month later, the victim showed police a letter Banks had mailed to him earlier in the year. Banks' writings detailed the sexual relationship between her and the victim, according to the affidavit.

His mother "had (Banks) pay her money for the acts to continue," police say in the affidavit.

Banks, who also was wanted for theft in York County, was arrested earlier this month by the U.S. Marshals Fugitive Task Force York Unit.

Banks was at York County Prison on those charges. As of Thursday night, she had failed to post bail.

Police did not say whether the boy remains in his mother's custody.

E-mail: bhambright@lnpnews.com