Police affidavit details alleged Grok use in Pennsylvania mall worker’s child-abuse case

Details of a police affidavit published October 27 allege that a Pennsylvania mall employee used Grok to turn a photograph of a teenage girl into child sexual abuse material. Investigators linked an identifiable child to the AI-generated material in the case against Robert J. Mayberry, who was arrested October 21 and faces 32 charges.

The Delaware County Daily Times published the detailed account of the affidavit on October 27, following NBC10’s earlier coverage of the arrest. Mayberry, 41, of Prospect Park, worked at the King of Prussia Mall. West Goshen police investigated both alleged covert recordings of women and girls and the creation of AI-generated abuse material.

The charges include offenses involving depictions of a child in a sex act, child sexual abuse material, invasion of privacy and criminal use of a communication facility. These are allegations, not findings of guilt; the case remains pending.

A park photograph linked to an AI video

One part of the affidavit concerns 48 photographs of a teenage girl at West Goshen Community Park. Investigators identified the girl, who was 14, and said she matched a girl depicted in an AI-generated video. Police attributed the creation of abuse material from her photograph to Grok.

The alleged connection involved more than a similar face. Police described matching clothing, a park setting and the girl’s seated position. Metadata dated the photographs to June 8 and the corresponding AI-generated video to June 10, according to the affidavit account.

Across the seized devices, investigators reported finding 76 AI-generated videos and 53 AI-generated images they characterized as indicative of child sexual abuse material. A file description indicated that 27 AI-generated items had been saved through Grok.com. Police also reported finding seven non-AI child-abuse images on a memory card.

The device and account records

The investigation began after Mayberry’s girlfriend reported finding disturbing images and videos in a password-protected hidden folder on his phone. She used her own phone to photograph some of the material and showed those photographs to detectives, according to the criminal complaint described by the Daily Times.

Officers later stopped Mayberry’s car in West Goshen to serve the warrant. They seized a MacBook, two phones, a flash drive and nine camera memory cards. Over the following weeks, investigators obtained further warrants to examine the devices and seek records from Google, Apple and Grok.

Records returned under the Grok warrant included text prompts associated with Mayberry’s account, but the videos were no longer available from the service. Investigators said they found hundreds of prompts describing child sexual abuse material and used to create image and video files.

The covert-recording allegations extend beyond AI generation. Investigators reported 153 videos showing attempts to record beneath women’s and girls’ skirts, with many subjects appearing to be young teenagers. Police believed recordings were made at the mall, retail stores and outdoor locations.

Bail posted, preliminary hearing ahead

District Judge Anthony diFrancesca set bail at 10% of $75,000, which Mayberry posted. His attorney, Steven F. O’Meara, had no comment when contacted by the Daily Times on Monday evening.

NBC10’s October 23 coverage listed the next preliminary hearing for October 30. The station also reported, citing sources, that Mayberry had been banned from the King of Prussia Mall. It had sought comment from the mall but had not received a statement at publication.