The widow of the police officer Andrew Harper – who was killed trying to apprehend three teenage thieves as they attempted to steal a quad bike – is launching a campaign for a law in her husband’s name under which criminals convicted of killing emergency services workers would spend the rest of their lives in jail. Lissie Harper, 28, who married her husband about a month before his death, wants the law changed so anyone who kills a police officer, firefighter, nurse, doctor or paramedic is jailed for life. The jail terms handed to the three teenagers who killed PC Harper as they tried to escape the scene of a crime are being considered by the attorney general under a scheme designed to let members of the public ask for a serious crown court sentence from England or Wales to be reviewed over concerns it was too lenient. The ringleader, 19-year-old Henry Long, was sentenced to 16 years in prison for the manslaughter of Harper, while his accomplices, Jessie Cole and Albert Bowers, both 18, were each jailed for 13 years. The three were cleared of murder. Lissie Harper intends to call for a change in the law in high-profile meetings with the prime minister, Boris Johnson, and the home secretary, Priti Patel. She said: “I pledge to my late husband to never stop until I have made the difference that this country clearly needs. I vow to stand strong and firm with so many other honourable people in our country to make the changes that we clearly know to be justified. “I hope that by creating a new ‘Andrew’s Law’ – that sees any person who commits a crime that results in the death of an emergency worker being jailed for life – that those that have to go through what I have been through in the future get the justice that they rightly deserve.” PC Harper’s mother, Debbie Adlam, launched a similar campaign on Wednesday for a “mandatory” 20-year minimum prison term for killers of police officers. She said: “We’ve come to realise that, with the outcome of the trial as it stands, something needs to change. “He is worth much more than this and we’ve been thinking for some time that something needs to be brought in to protect our police officers.” The Thames Valley officer became entangled in a tow rope attached to his killers’ Seat Toledo and was dragged at “breakneck” speed for more than a mile along country lanes before he was dislodged, having sustained horrific injuries. The three teenagers claimed the incident was a “freak event” that none of them could have planned or foreseen. The prosecution said the defendants must have been aware Harper, who was over 6ft and weighed 14 stone, was being dragged to his death. Lissie Harper previously condemned the murder acquittals and later wrote to Boris Johnson to ask for a retrial.