Story By:  Ana Marjanovic, Sub-Editor: Michael Leidig, Agency:  Newsflash

A gunman who shot his teenage ex-girlfriend dead in the street has been caught by the police after a horrified witness filmed the slaying.

The footage, filmed from a window on a mobile phone, shows 19-year-old Asiye Nur Atalay screaming for her life as her killer closes in while holding a handgun.

Then, as she falls to the pavement with her arms flailing, he apparently shoots her in the head at point-blank range and then flees the scene.

The terrifying killing took place in the Esenler district of Istanbul, Turkey, after nightfall on Wednesday, 4th May.

Eyewitness Sibel Hasten said the gunman aimed his weapon at the teen, causing her to fall to the ground in shock as he approached her.

She said that after the teen shouted “go away”, the gunman fired at her head and then ran off down the street.

After the suspect, named as 25-year-old Umit Karakoyun, fled, paramedics arrived on the scene, but Asiye was too seriously injured to survive.

The suspect was swiftly apprehended at a residence in the Arnavutkoy neighbourhood, where he had gone into hiding.

He was taken to the Atisalani Police Station, in Esenler.

He was found to have an extensive criminal record of 16 counts of five crimes, including drug trafficking, deliberate injury, threatening behaviour, and looting and theft of motorcycles and animals.

It is unclear if he has been charged over the slaying and what his alleged motive was.