Murders linked by sick urge to control women

In both cases he targeted and manipulated vulnerable women before turning to violence against men in their lives who stood in his way.

"It is at the point that his control in these relationships is challenged that he reacts with extreme and totally disproportionate violence, in both cases being prepared to commit murder," said Det Supt Chris Thompson, the senior investigating officer in the West Yorkshire case.

In both cases he also wrote letters protesting his innocence.

It was in December 1971, while on the run after failing to return from weekend parole to Pentonville Prison where he was serving a five-year sentence for burglary, Wright brutally murdered Trevor Hale, 28.

He had started to see Mr Hale's wife Ruth and lived with her for around 18 months after the killing. She bore him a daughter who was to grow up while her father was serving the next 26 years in jail.

He was recaptured in early 1973 and convicted later that year at Chelmsford Crown Court of murdering Mr Hale after the jury heard the gruesome details surrounding the killing.

He first battered his rival to death with an iron bar at his caravan which he had parked near a deserted airfield in Buckinghamshire. Later he dug a 12in deep pit to hold the body which he then tried to cremate using oil and wood.

It was alleged at the trial that he even took Mrs Hale from her home in Aylesbury to the site to watch.

She was still standing by him at the time, although he tried to blame her for her husband's death saying she struck him with a steering lock when the pair of them were fighting over her.

Wright returned to West Yorkshire on licence after his release in 1999 where it was suspected he continued as a burglar.

He then met Melissa Crocker in 2008 when she became a neighbour moving into the flat below him in Howarth Crescent, Bradford. Miss Crocker, 57, is physically disabled having had her right leg amputated, and uses a false leg.

She also has mental health issues and her community support worker considered her "vulnerable to manipulation" and would spend whatever money she had right away.

Her disability benefits had previously been paid into the bank account of her son Craig Freear, who lived with his boyfriend Neville Corby, later to become Wright's next murder victim.

Mr Freear would pay bills and do her shopping.

However, after Wright came into the picture he persuaded her to start having the benefits paid into his account instead.

She called Wright one of the kindest men she had met even after he had tried to kill her son.

The proposed changes led to increasing friction between Wright and Mr Freear who were not happy with his attempts to control Miss Crocker.

This included moving her to a rented home in Stubbings Way, Shipley, near his caravan.

After violent confrontations between Mr Corby and Wright he shot the two men, although Mr Freear survived.

Wright then went on the run for 30 days during which he sent letters to Det Supt Thompson protesting his innocence claiming he was elsewhere with Miss Crocker at the time.

"He claimed he was a victim and threatened suicide and we know that he wrote similar letters of a self-pitying nature following the 1971 murder conviction," Det Supt Thompson said.

Double killer trapped by 'alibi' lies

Detectives believe that double killer Ernest Wright took the unusual step of writing letters to the senior officer in the case while on the run was part of his plan to build up an alibi to put forward as his defence.

Butinstead his protestations of innocence in the letters turned out in the words of Det Supt Chris Thompson to be a "gift to the investigating officers."

Wright detailed times and places where he claimed to be at the time of the killing, but the police were able to prove his alibi was "based on a tissue of lies".

"We could show the timings of his account were far from the truth," he said.