Crown prosecutors at the trial of a Saskatoon man facing four child pornography-related charges are trying to prove he’s behind the alleged luring and blackmailing of a teen girl with cognitive issues.

The charges against Abdul Jat, who was 19 when he was detained by police in July 2016, include child luring, possession of child pornography, distributing child pornography and extortion to obtain intimate images.

He’s pleaded not guilty, but the Crown aims to prove Jat was the one who sent a Facebook friend request to the girl two years ago, convinced her to send nude photos and then used those pictures as blackmail if she turned down a request for sex.

The girl was 17 at the time of the friend request and accepted the request because she thought the user was a friend from school, court heard.

Some of the testimonies and evidence in the case were under a voir dire — essentially, a trial within a trial that determines if the evidence is admissible in court — until a judge ruled them admissible.

Jat’s defence lawyer has been arguing his client was not the sole user of the smartphone.

A forensic technician testified Wednesday a phone seized from Jat — and which the techinician said belonged to Jat — contained 18 photographs of the victim and 49 user accounts, as well as conversations with the victim.

The trial is set to continue Friday.