£400,000 - the cost of investigating trio of Hartlepool murder cases

Investigations into the killings of Norma Bell, Angela Wrightson and Mark Denton cost almost £400,000 to carry out.

The murder of grandmother Mrs Bell, a widow who had fostered more than 50 children, cost £270,444 to complete.

Mrs Bell, 79, was killed at her Westbourne Road home in Hartlepool by Gareth Dack in April 2016.

After strangling Mrs Bell he used her landline to call TV sex chat lines and tried to cause a gas explosion to destroy the evidence.

Dack, a father of four and small-time cocaine delaer, also ransacked Mrs Bell’s home stealing hundreds of pounds in cash and a flat screen TV that he sold to a friend that same night.

He was given a 33-year sentence after being found guilty of her murder at Teesside Crown Court.

The shocking murder of Hartlepool woman Angela Wrightson in her own home by two schoolgirls cost the force £64,649, it was revealed.

The teenagers, who were 13 and 14 at the time of the killing posed for Snapchat selfies while putting 39-year-old Ms Wrightson through a five-hour ordeal in December 2014.

The victim suffered a horrific and prolonged attack at her home in Stephen Street.

She was hit with a shovel, a TV, a coffee table and a stick studded with screws as well as various other items after she let the girls into her home.

The victim would often let school children drink in her living room.

Ms Wrightson, who was 5ft 4in and weighed six-and-a-half stone, was found dead in her blood-spattered living room the next morning.

A selfie posted to Snapchat showed the defendants smiling with Miss Wrightson pictured in the background shortly before her death.

After the attack, the girls even boasted to friends about being given a lift home by police, who were unaware of the murder.

Both teenagers received life sentences at Leeds Crown Court in 2016 and were told they must serve a minimum of 15 years behind bars for the crime.

And the horrific axe murder of former Hartlepool boxer Mark Denton cost the force a total of £61,692 to investigate.

Anthony Middleton, 21, and David Sowerby, 24, were both convicted of the killing at a New Year’s Eve House party in Hutton Avenue, in the town on New Year’s Eve 2013.

On the fateful night of the murder, Mark and his girlfriend Sarah Kinnie had been planning to go to a concert in Middlesbrough to celebrate New Year’s Eve.

And as he left the house, Mark told his mum Ann that it was to be his last “big” night out as he planned to take up bodybuilding in the new year.

Sowerby was sentenced to life in jail, with a minimum of 27 years.

Middleton also received a life sentence and will serve a minimum of 23 years.

Among the other high profile cases listed in the top 10 most expensive cases investigated by Cleveland Police over the past five years were the shooting of Lee Petite, which cost £154,022, the ongoing investigation into the disappearance of Naheed Khan, which has so far cost £99,860, and the killing of Jessica Patel by her husband, pharmacist Mitesh Patel, who strangled and suffocated her and then staged a burglary at the couple’s home in Middlesbrough in May last year which cost £60,314.

Cleveland Police declined to comment on the figures