Breakthrough in DNA testing could finally help cops find mystery killer who gunned down UK family and French cyclist in the Alps 12 years ago

The gun used to murder three members of a British family and a French cyclist in the Alps may yet hold the key to catching the killer, investigators believe.

A breakthrough in DNA testing means the baffling 12-year-old cold case might finally be solved, it emerged on Thursday.

It was in September 2012 that 50-year-old Surrey engineer Saad al-Hilli was gunned down alongside his wife, Iqbal Al-Hilli, 47, and her mother, Suhaila al-Allaf, 74.

The bloodbath in an isolated layby close to Lake Annecy, in eastern France, also claimed the life of cyclist Sylvain Mollier, 45.

The al-Hilli’s seven-year-old daughter, Zainab Al-Hilli, was shot in the shoulder and beaten around the head, while her sister, Zeena Al-Halli, four, escaped by hiding in the back of the family’s BMW car.

The bloodbath in an isolated layby close to Lake Annecy, in eastern France , also claimed the life of cyclist Sylvain Mollier (pictured), 45

The al-Hilli’s seven-year-old daughter, Zainab Al-Hilli, was shot in the shoulder and beaten around the head, while her sister, Zeena Al-Halli, four, escaped by hiding in the back of the family’s BMW car

It was confirmed early in the investigation that a Luger PO6, Parabellum 7.65, was used to carry out the massacre, after fragments of the vintage Swiss Army weapon were found on the ground

It was confirmed early in the investigation that a Luger PO6, Parabellum 7.65, was used to carry out the massacre, after fragments of the vintage Swiss Army weapon were found on the ground.

Now, investigators from France’s elite cold case unit in the Paris suburb of Nanterre have ordered the ‘unsealing of the fragments’ so they can be re-tested with state-of-the-art DNA technology.

The clothes Sylvian Mollier and Zainab Al-Hilli were wearing on the fateful day are also going to be reexamined, along with some 10 cigarette butts found around the area.

‘It is hoped that new examinations will uncover DNA traces,’ said an investigating source. ‘If yes, then they will be sent for comparison with a national genetic fingerprint file which lists more than four million fingerprints, to see if there is a match.’

DNA can be obtained from even a single fingerprint, and analysis has improved significantly since the Alps murders investigation was first launched, said the source.

Mr Mollier, a father of three, was wearing a helmet, cycling shoes, and sports clothing when he was killed, and all of it will be analysed by a specialist laboratory in the Paris area, along with Zainab’s clothes and shoes.

But it is the gun which holds the most hope of a breakthrough, as it is guaranteed to have been in direct contact with the killer.

Most of the Luger was removed from the scene, but small pieces of the grip plates were found near the BMW.

In January, a cold case dating back to 2008 was solved in France thanks to new DNA testing.

The body of Caroline Marcel, a 45-year-old jogger was found half submerged in a river, and the new testing methods matched DNA found on her corpse with DNA held in the national database, leading to the arrest of a known sex offender.