David Johnson, 35, was arrested after a fellow train passenger spotted him watching child abuse videos on a Stafford-to-London service in September 2025 and alerted British Transport Police. A subsequent investigation revealed the scale of his offending went far beyond that incident: analysis of his devices uncovered nearly 200 indecent images, including 105 of the most serious category, and messages showed he had been trying to buy a 13-year-old girl to abuse.

Police found Johnson had arranged to pay £4,500 in instalments to a woman claiming to be the girl's "guardian" and was en route to meet the child, carrying condoms and a train ticket, on the day of his arrest. It later emerged that the girl and her supposed guardian were fake personas run by scammers in Nigeria, to whom Johnson had been sending money. He pleaded guilty at Inner London Crown Court to six counts of making indecent images of children, two counts of attempting sexual communication with a child, and arranging a child sex offence, and was sentenced to two years and three months in prison along with a 10-year Sexual Harm Prevention Order and lifelong entry on the sex offenders' register for a decade.