A judge has warned of the danger of knife crime after locking up a 17-year-old boy who stabbed a drunken man at a skate park in Sidmouth.

The teenager was fighting with the 25-year-old victim when a friend handed him a knife and he used it to stab him in the armpit.

The boy was ordered to receive 18 months’ detention and training by Judge Phillip Wassall, at Exeter Crown Court, after admitting wounding with intent to cause grievous bodily harm.

The judge said an immediate sentence was imperative to deter other young people from carrying or using knives.

He said: “Whenever anyone uses a knife and stabs somebody, it must result in a substantial prison sentence. The message has to go out to people who carry knives or pass them to other people that there must be a deterrent.

“When people involve themselves with this type of crime, there can be only one result. The courts see too many occasions where young people become involved in knife crime.

“Luckily, in this case, the injury was not as severe as it might have been and somebody did not die, but too often incidents with knives end with tragic results.”

Emily Pitts, prosecuting, said victim Terence Carnell had been drinking for around eight hours and had consumed nine cans of lager and part of a bottle of wine before getting involved in an initial fracas with the 17-year-old at Manstone skate park in July.

The boy challenged him to a fight and there was a scrap, which left the older man with a bloody nose. He went home to clean himself up, but returned and there was a second violent encounter.

Miss Pitts said: “The man was very angry and wanted to fight. The boy said he would ‘have you’ and punched him. Mr Carnell retaliated, but missed because he was drunk. The defendant jabbed at him under his right arm and some girls who were present asked the boy why he had stabbed him. The victim suffered a two-and-a-half centimetre laceration and scratch in his armpit.

“The defendant ran off and was found in a garden of a house nearby, where the owner described his demeanour as like that of a little boy who had done something wrong and was petrified.”

Nigel Wraith, defending, said the boy regretted his actions immediately and has shown true remorse. The victim had written to the court, urging the judge not to send the boy to jail.