Yesterday, the jury found a 16-year-old boy guilty of endangering the safety of rail users by putting the obstacles over railway lines at Black Bridge, in Stanground, Peterborough, after a train struck the items on October 22 last year.

Judge Sean Enright made the decision to lift an order banning the publication of his name, and today The Evening Telegraph can reveal he is Joe Lynch.

The photo, taken on Lynch's mobile phone as one of the two boys crouched down by the tracks after putting the 9st 7lbs slab and 10ft-long metal trimming across, was a key piece of evidence in the case.

But, following three hours of deliberations, the jury found Lynch and his 17-year-old co-defendant not guilty of the main charge of endanger the safety of passengers with intent – the graver of the two.

The 17-year-old had earlier admitted the lesser charge (without intent). His name, however, cannot be revealed as he is facing a trial for a separate matter.

Judge Sean Enright said custody would be "inevitable" in both cases.

The court had heard how the pair had a fascination with putting things on the line, and it had escalated from small items, such as pebbles and pennies, to a bottle and a pile of stones.

In his summing up, the judge told how they had admitted they "got a kick" out of watching the items being crushed by trains and exploding, and taking pictures which they shared.

The defence counsel for the 17-year-old, Georgina Gibbs, said while her client's conduct may have been "mindlessly stupid" and "reckless", he didn't intend to derail the train and put passengers at risk.

And Simon Gladwell, defending Lynch, of Blackmead, Orton Malborne, Peterborough, said Lynch didn't actively participate in putting the items on the line.

The court heard that the evidence showed the defendants were part of a small group of boys who hung around Black Bridge,

Then there came a time when they started to stray on to the line and put items on it.

On October 22, five of the group went to Asda, in the city centre. From there, they went to Black Bridge. Two of the accused then went up on the tracks.

One of the group, a prosecution witness, earlier told the court that the 17-year-old told him he was going to place a block and metal on the tracks as he had allegedly done two weeks before the incident – a claim which the defendant denied.

The court heard that on the fateful day, the train driver was travelling at 60mph when he spotted the obstructions and took fright. He slammed on his emergency brakes and prepared himself for the impact.