A former soldier who shocked the nation when he slaughtered his mother and her partner in an horrific crossbow killing has won a cut in his sentence.

Killer David Nicholson was just 17 when he executed his mother Ann and her partner of 11 years Billy Kent in cold blood.

In the summer of 1990, Nicholson had deserted his regiment following a car crash and returned to his home in Fatfield, near Washington.

While his mother was out shopping, the teenager coolly shot Billy Kent through the head with a crossbow bolt - although he did not die immediately.

He pulled the bolt from his victim's head, reloaded the weapon and waited for his mother to return - shooting her through the head as she opened the door.

He then reloaded once more and finished off Mr Kent with a bolt through the chest at close range.

Nicholson then hid the lifeless bodies under garden furniture and carried on living in the house - telling neighbours the couple had gone on holiday.

But the shocking truth was discovered when he was arrested by military police for being absent without leave - and his brother discovered the hidden corpses.

The killing provoked outrage across the North-East and calls for changes to the law after it emerged that Nicholson had bought the murder weapon across the counter in Newcastle the day before the killing.

Nicholson admitted the killings, claiming he had snapped, and at Newcastle Crown Court six months later was ordered to be detained at Her Majesty's pleasure.

Yesterday, England's most senior judge, the Lord Chief Justice, Lord Woolf, heard that Nicholson as showing some signs of progress after 12 years in custody.

In 1991, the Home Secretary ordered the killer must serve 18 years before being considered for parole - but yesterday Lord Woolf cut the tariff by 12 months.

Lord Woolf said: "Nicholson is reported to talk of the offence in a very calm, measured and cold way which report writers see as consistent with evidence indicating that he carried out the murders in a cold and detached manner."

Nevertheless, the judge said Nicholson had completed an alcohol awareness course and his behaviour in prison had been described by officers as mostly acceptable.