A child sex offender seen watching child abuse footage on a London-bound train had also attempted to purchase a 13-year-old girl and pay for her in instalments, investigators found.
David Johnson, 35, was exposed after a fellow passenger noticed him viewing videos showing young children being abused during a journey from Stafford to London on September 23, 2025.
Messages recovered from his device showed a supplier telling him: “I got all videos. Don’t worry, sweetheart [I] supply all kinds of videos.[sic]” Johnson replied: “Just kids videos”.
What Johnson did not realise was that a shocked passenger seated behind him had seen both the disturbing exchange and the illegal material that appeared on his screen moments later.
The witness moved to another carriage and contacted British Transport Police, prompting officers to meet the train and arrest Johnson when it arrived at London Euston.
Police seized his mobile phone and discovered that an indecent image of a child had been set as the device’s wallpaper, although prosecutors said further evidence was needed before charges could be brought.
Even while in custody, Johnson asked officers to return the phone, claiming he “needed to delete some stuff”.
A wider forensic examination of 150 electronic items linked to him later uncovered almost 200 indecent images of children, including 105 Category A images, the most severe classification.
In an episode of Channel 4’s 999: What Happened Next, it was also uncovered that Johnson was trying to buy a 13-year-old girl named Lola.
David Johnson, pictured, was sentenced at Inner London Crown Court to two years and three months behind bars
Unbeknownst to him, a horrified passenger sitting behind him witnessed the disturbing exchange about child abuse content as well as the videos that followed
Officers found Johnson had been sending disturbing and explicit messages to the teen across several apps.
Messages found by police implied Lola was owned by an individual named ‘Shanelle’ and that Johnson would have to pay a fee to meet her.
In correspondence between Johnson and Shanelle, she describes herself as the teenager’s ‘guardian’.
She claimed the 13-year-old had been abandoned by her biological mother outside of a ‘crack house’ when she was a baby.
Shanelle then alleged they never heard from Lola’s mother again and that she had taken her own life.
Johnson later responded: ‘Okay, and I am sorry to hear that and you know I will look after her.’
Shanelle then asked: ‘Are you interested in sleeping with her, or [do] you wanna have her forever?’ To which Johnson responded: ‘Both.’
She then drew up a contract setting out a payment plan for Johnson to pay £4,500 in increments over a number of months.
Johnson had planned to meet the 13-year-old girl at her home on the day of his arrest and had condoms and a train ticket in his possession at the time.
Police went to an address in Wolverhampton where they believed Lola was living; however, people living there did not know anything about the child.
It was later uncovered that neither Lola nor Shanelle were real and were fake personas created by scammers in Nigeria to whom he was sending money.
Johnson had previously gone to Wolverhampton to pick Lola up but was told she was sick and was asked to return at a later date to get her.
Johnson had gone to pick Lola up from that location but was told over messages that she was sick, and they asked him to return at a later date to get her.
Johnson offered no comment during police interviews, and devices were seized from two addresses linked to him.
Paedophile Johnson pictured being arrested by police who swooped in after a fellow train passenger saw him watching child abuse videos
At Inner London Crown Court, he pleaded guilty to six counts of making indecent images of children, two counts of attempting to engage in sexual communication with a child and arranging a child sex offence.
He was sentenced to two years and three months behind bars last April. He was also handed a 10-year Sexual Harm Prevention Order.
Johnson will remain on the sex offenders’ register for a decade.
Detective Constable Victoria Lowth said: ‘The quick thinking and courage of the man who saw Johnson’s phone meant that we were able to quickly arrest him and uncover the scale of his offending.
‘I’d like to offer our sincerest thanks to that man, whose actions have directly led to Johnson’s imprisonment.
‘Behind every image and video Johnson owned is a vulnerable child that has been exploited and abused.
‘He is clearly a danger to children and has rightly been handed a substantial jail sentence, and stringent conditions have been put in place to prevent him from offending further.
‘We will always do everything we can to make the railway a hostile place for criminals, and especially those whose offending targets children.’
