US Magistrate Judge Lindsay Griffin in Tampa wrote in a two-page order on Friday the initial court appearance of 82-year-old Thomas Markle, included a "lack of recall" and raised questions in her mind as to whether he was competent to face prosecution.
Markle was arrested on Friday on a single federal count of possessing child sexual abuse material, including two explicit photographs of himself posed with a naked underage girl and other images of him with children in various stages of undress.
According to an FBI affidavit filed in court as part of the criminal complaint lodged against Markle, federal agents seized the material in question, part of a cache of slides, film negatives and books, from storage units Markle had rented in Los Angeles since 2008.
Commenting on the case, FBI director Kash Patel said Markle "targeted innocent children and sought to steal their innocence through his criminal actions."
Markle was most recently residing in Lakeland, Florida, where according to the Daily Mail newspaper, he was a nursing home patient.
No plea was entered during Friday's hearing, and the judge permitted Markle to be released from custody on personal recognisance on condition that he submit to home detention and electronic monitoring.
Federal public defender assigned to represent Markle, Mary Claire Wolf, did not immediately respond to a request for comment.
In a court order after the hearing, Griffin said she found "reasonable cause to believe" that Markle may "suffer from a mental disease or defect rendering him mentally incompetent to the extent that he is unable to understand the nature and consequences of the proceedings against him or to assist properly in his defence."
Griffin said she based her findings on unspecified information provided about his health condition, his "advanced age, and lack of recall."
The judge also appointed Dr Amie Gerodimos, a forensic psychiatrist, to conduct an independent psychiatric exam of Markle and to render a diagnosis of his condition with a finding on his mental fitness to stand trial.
Griffin set a November 20 deadline for Gerodimos to report back to the court.
1800 RESPECT (1800 737 732)
National Sexual Abuse and Redress Support Service 1800 211 028
Lifeline 13 11 14
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