A chief constable has backed the widow of Pc Andrew Harper in calling for whole life sentences for those who kill police officers during the course of a crime.

Northamptonshire Police Chief Constable Nick Adderley said “those who set out to commit a crime” in which an officer is killed should “automatically be sanctioned by a whole life term”.

Pc Harper’s widow, Lissie Harper, launched a campaign for “Andrew’s Law” on Wednesday, backed by the Police Federation of England and Wales – calling for full-life prison terms for those who kill emergency services workers.

The police constable’s mother, Debbie Adlam, also called for tougher sentences, telling the PA news agency that “something needs to change” after those responsible for her son’s death were handed 16-year and 13-year sentences at the Old Bailey on July 31.

The 28-year-old Thames Valley Police officer died as he tried to stop three thieves fleeing after they stole a quad bike in Stanford Dingley, Berkshire, on August 15 last year.

Henry Long, 19, and 18-year-olds Jessie Cole and Albert Bowers were sentenced for the newlywed’s manslaughter.

Pc Harper was caught in a crane strap dangling from the back of a Seat Toledo driven by Long, and dragged to his death.

Mr Adderley made his comments in a Facebook Q&A as he started his third year as the head of the Northamptonshire force.

He said he believed life imprisonment was necessary based on his experience at Greater Manchester Police in 2012, when Nicola Hughes and Fiona Bone were killed in a gun and grenade ambush.

He said: “It’s a very sensitive issue for the family of Andrew Harper of course but it’s also a really sensitive issue for the police family and quite rightly so.

“I do believe – I’ve said quite clearly based on my own experiences when Nicola and Fiona were murdered in Manchester – anyone who is in the commission of a crime, who assaults and kills a police officer, should face a whole term tariff.

“They should face life imprisonment.

“The bit about where the law gets really complicated around murder and manslaughter is this bit – did you set out to murder somebody or did they just happen to get killed as a consequence?

“For me, if you set out to commit a crime, and in the commission of that crime a police officer is killed, for me what they call in Latin ‘mens rea’ is laid out, and for me that should automatically be sanctioned by a whole life term – life imprisonment.”