A gunman who shot three of his colleagues and a police officer in a terrifying bloodbath has been euthanised before he could stand trial after claiming his injuries from a police gun battle left him in agony.

Marin Eugen Sabau, 45, was due to stand trial for wounding three former colleagues and a police officer in the shootout, which took place in the city of Tarragona, Spain after he was fired.

But ‘The Gunman of Tarragona’, as he had been dubbed, claimed that his injuries made his life unbearable and asked a judge to allow him to use Spain’s new euthanasia laws.

Sabau had been left paralysed from the neck down and lost a leg that had to be amputated. He claimed he suffered from severe constant pain and an injured hand.

A court in Tarragona ruled it was the former security guard’s fundamental right to request euthanasia, outweighing his victims’ call for justice.

Prison authorities on 23rd August confirmed Sabau’s death by lethal injection, reported local media.

Sabau became known as ‘The Gunman of Tarragona’ after shooting three former colleagues after he was fired. He then shot a police officer.

Sabau then sent a text message to his bosses while hiding out in an abandoned farmhouse saying: “Happy holidays, you bastards.”

He was eventually seized after a police shootout.

Sabau reportedly showed no signs of regret before he was euthanised.

His victims had argued against letting the procedure go ahead.

They all suffered horrific injuries and hoped to see the gunman stand trial.

Sabau was facing charges including attempted murder, armed assault and illegal possession of a firearm.

Months after his arrest, Sabau – being held in the Terrassa Penitentiary Hospital – requested to be euthanised due to chronic pain.

A petition endorsed by his doctors was granted by a judge who ruled that the gunman’s right to personal freedom and dignity eclipsed the public’s right to a fair trial.

In June last year, Spain became one of the first countries to legalise euthanasia, a decision that was supported by over 80 per cent of Spaniards but was highly criticised by the Catholic church.

Sabau agreed to have his organs donated directly after the procedure which was reportedly quick and painless.