Jurors and others in Judge Donald Thompson’s courtroom kept hearing a strange whooshing noise, like a bicycle pump or maybe a blood pressure cuff. During one trial, Thompson seemed so distracted that some jurors thought he was playing a handheld video game or tying fly-fishing lures behind the bench.

The explanation, investigators say, is even stranger than some imagined: The judge had a habit of masturbating with a penis pump under his robe during trials.