A 71-year-old former pastor from Montgomery County pleaded guilty Monday to forcing a girl to pose for sexually explicit photos and videos, and amassing more than 10,000 images of child pornography.

Appearing in federal court in Philadelphia, Jerry William Zweitzig of Hatboro withdrew his not-guilty plea and admitted to manufacturing and possessing child pornography. “I plead guilty to all six counts against me,” Zweitzig told U.S. District Judge Wendy Beetlestone.

Zweitzig, a pastor at Horsham Bible Church until his 2016 retirement, faces at least 15 years in prison when he is sentenced next year.

As Assistant U.S. Attorney Eric Gibson read a detailed summary of the charges against him, Zweitzig kept his gaze down.

The victim, born in 2003, first reported the abuse to her parents in 2014, shortly before they moved from Pennsylvania. Investigators later found a video, 13 minutes long, in which Zweitzig is seen telling the girl that he would miss her, that she could do anything with him sexually but he would never force her, and that she shouldn’t tell anyone about what they did together.

He told her he had taken explicit photos of her when she was 9 and said he wanted to take more. As Zweitzig removed his clothes and began touching himself in front of her, the child fled the room. She locked herself in the bathroom and called her parents to tell them about the abuse, Gibson said.

Her father went to the police, but for reasons that are not clear, no charges were filed against Zweitzig. After the family moved from Pennsylvania, Zweitzig sent the girl letters, including pages from his journal about her.

In 2018, she gave investigators a more detailed report about the abuse, which she said lasted from 2009 to 2014. Authorities searched Zweitzig’s home and arrested him in December 2018.

Homeland Security Investigations agents found pornographic images and videos from 2013 and 2014 featuring the girl. They also found thousands of images of children downloaded on computers, flash drives, hard drives, and digital cameras.

Zweitzig’s relatives attended the hearing. As it began, two women in the gallery were crying. Neither Zweitzig’s victim nor her family members attended, the prosecutor said.

Zweitzig, wearing glasses and a khaki prison jumpsuit, told the judge he felt “nervous,” adding, “Other than that, fine, thank you.”

Beetlestone scheduled his sentencing for Feb. 5.