A FORMER Government scientist who booby-trapped his home to deter burglars has been jailed for 18 months.

Because a judge said he considered Nigel Cockburn to be a danger, an extended licence period of 18 months was imposed.

He told the 53-year-old "eccentric", who worked for the Ministry of Defence for 36 years: "The nature of your former occupation makes you potentially very dangerous. You are an expert in counter-terrorism and have considerable experience in dealing with explosive devices."

Maidstone Crown Court heard that Cockburn invented a lethal mantrap which injured an Army explosives expert when he opened the door of a rundown shed and a metal device packed with 4in nails swung at his head.

Captain Iain Swan, of the Royal Logistics Corps, suffered wounds to his arm as he instinctively raised it to protect head.

The trap was discovered after police were called to a garage fire at the row of three dilapidated cottages Cockburn owned in Wood Street, Swanley Village, near Dartford, on July 10 last year.

Firefighters discovered live ammunition for 9mm and .38 guns in the garage. Officers also found chemicals, CCTV cameras and tubs of weedkiller.

Capt Swan found the mantrap in a shed about 400m from the cottages. He had pushed open the sliding doors, which were blocked with two gas cylinders.

Cockburn, of Cloonmore Avenue, Orpington, was cautioned in 2004 after he wired up the mains to a door, so that intruders would get a shock.

Cockburn, who worked at Fort Halstead MoD research site in Sevenoaks, said he had been burgled 20 times in 14 years and the police had done nothing about it.

He denied wounding with intent, an alternative charge of assault causing actual bodily harm, setting a mantrap, and possessing ammunition without a certificate.

He was cleared of the wounding charge but convicted of the remaining counts.

Recorder Christopher Wilson said Cockburn had told a psychiatrist that he set the mantrap to deter the local travelling community and it was through Capt Swan's own stupidity that he was hurt.

Cockburn was jailed for 18 months on the mantrap charge, with 18 months extended licence, 12 months on the assault charge and three months for the ammunition offence.