Forty days into the gruesome murder of teenage boy Samiul Islam Rajon, police yesterday pressed charges against 13 people, including prime accused Kamrul Islam, for their involvement in the killing.

In the charge sheet submitted to a Sylhet court, police showed three accused, including Kamrul, absconding and 10 others arrested.

Kamrul fled to Saudi Arabia soon after the incident. He was later detained by Saudi police. Despite Bangladesh government's diplomatic efforts to bring him back, the Saudi authorities are yet to make it clear when they will repatriate him.

Talking to The Daily Star yesterday, a foreign ministry official said, "Saudi government has promised us that it will send back Kamrul."

The official, however, said the Saudi authorities didn't mention any date for Kamrul's repatriation.

"Our embassy there is working hard to that end," said the official on condition of anonymity.

Around 5:00pm yesterday, Investigation Officer Suranjit Talukder, also an inspector of the Detective Branch of Sylhet Metropolitan Police, submitted the charge sheet to the court of Metropolitan Magistrate Shahedul Karim.

Apart from Kamrul, the other accused are Muhit Alam, Ali Haider, Nurul Amin, Dulal Ahmed, Nur Mia, Ayaz Ali, Badal, Firoz Ali, Shamim, Ruhul Amin, Pavel and Asmat Ali.

The investigation officer prayed to the court for relieving two other detainees -- Lipi Begum and Ismail Hossain Ablush -- of the charges as their involvement in the incident was not found, said police.

Public Prosecutor Misbahuddin Siraj said eight of the arrestees confessed to police their involvement in the killing.

Rajon's father Sheikh Azizur Rahman expressed satisfaction at the charge sheet.

"I will feel relieved when the culprits walk the gallows. I want speedy trial," he told The Daily Star.

On July 8, thirteen-year-old Rajon was beaten to death by Kamrul and several other brutes in Kumargaon Bus Stand area of Sylhet Sadar upazila.

His "crime", they claimed, was trying to steal a rickshaw van. One of culprits filmed the murder incident on a mobile phone and shared it on the social media.

The sickening torture video shook the nation to its core and stirred outcries in the social network and the mainstream media.

Tied to a pole, the boy screamed for help, cried for water and begged for his life. But the group showed no mercy. They laughed, joked and filmed their madness to show it off to people.

In the video footage that went viral, Kamrul, in a black T-shirt and lungi, was seen hitting the boy with a stick in the feet, joints of legs, shoulders and in the head.

They kept beating him, at times knocking him down to the ground, and asking how he would like to take the beating. When Rajon cried for water, they told him to drink his own sweat.

The boy died of brain haemorrhage. His body bore 64 injury marks.

After the killing, the culprits were taking his body on a microbus to dump it in a secluded place, but the locals spotted them and managed to catch one of them. The police recovered the body from the microbus.

A murder case was filed with Jalalabad Police Station on July 8 night.

On July 13, some expatriate Bangladeshis spotted Kamrul in Jeddah, caught him and handed him over to the Bangladesh mission there. Later, Jeddah police took him into custody.

Sylhet Metropolitan Police closed officer-in-charge of Jalalabad Police Station Alamgir Hossain and suspended sub-inspectors Aminul Islam and Zakir Hossain on July 24 after a probe found their negligence in arresting the killers.

Our Moulvibazar correspondent contributed to this report.