Prosecutors have demanded a 24-year-prison sentence for a teenage barber accused of stabbing a young schoolgirl to death and then calmly returning to work to shave 11 customers.

The incident occurred in the city of Edirne, Turkey, on 5th April, when Gulden Coni, said to be 14 in some local reports and 16 in others, was found dead in the grounds of the Edirne Vocational and Technical Anatolian High School.

The suspect, identified only as E.A., aged 15, allegedly changed his bloodstained clothes after the attack and proceeded to his workplace, a local barbershop, where he served 11 clients before being arrested.

Gulden Coni poses in undated photo. She was stabbed to death in Edirne, Turkey. Note: Private photo taken from local media. (Newsflash/NX)

E.A. reportedly told police that he was Gulden's boyfriend, a claim disputed by her father, Sami Coni, who stated: "He was not my daughter's boyfriend.

"He was obsessed with my baby and stabbed her over and over again in a planned, calculated manner."

Sami further alleged that the suspect had premeditated the murder, saying: "He'd planned it all the day before he killed her."

He also expressed frustration over the initial response from the suspect's parents, stating: "His parents didn't admit to the murder at first."

Picture shows the suspect (middle), undated. He allegedly killed Gulden Coni. Note: Image is a screenshot from video. (Newsflash/NX)

The victim's body remained at the crime scene for eight hours before being discovered, adding to the family's anguish.

Prosecutors have charged E.A. with murder and are seeking a prison sentence of 18 to 24 years, which the maximum possible term in line with juvenile sentencing guidelines.

E.A.'s trial is set to begin on 13th June at the Edirne 3rd High Criminal Court.

(MJ Leidig/newsX)