He started sexually abusing his victim when she was 12, said police.
The crimes continued for three years, until someone went to police on the victim's behalf.
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Merritt, who lives in Claymont, Del., was arrested on Wednesday after a three-week investigation.
He told police, "I need to seek professional help for this sin that has cursed me," according to court documents.
Figuring out Merritt's background as an ordained minister has been a challenge.
No one seems to know where he preached or practiced.
Merritt did work for a church. He worked on the website for Victory Christian Fellowship Church in New Castle.
But the pastor there says Merritt was only an employee and has since been fired.
He didn't attend church services and never had any contact with children, according to Pastor Gary Whetland.
No one there was even aware Merritt was ordained, said Whetland.
Merritt has been arraigned on eight rape charges.
He was in custody Friday at the Howard Young Prison because he couldn't make his $435,000 bail.