The police on Wednesday arrested the person who videotaped Rajon's torture and also participated in beating him up on Wednesday night.
Rajon, a 13-year-old boy was lynched by a group of goons on July 8 accusing him of stealing a rickshaw van. 
Akter Hossain, Officer-in-Charge (OC) of Jalalabad Thana of Sylhet, told the Daily Observer that Nur Mia, 20, also one of the torturers of Rajon, was caught by locals from Jangail area of Jalalabad. Nur Mia works at a workshop in Kumargaon in Jalalabad which is near the place where Rajon was beaten to death.
The OC also said that preliminary interrogation of the main accused, Kamrul Islam, in Jeddha also confirmed that Nur Mia actively participated in the gruesome murder of Rajon. Kamrul was arrested in Jeddah on July 13. He is awaiting repatriation home.
Meanwhile, Nizam Uddin, the father of Nur Mia, said if his son was found guilty of the crime he must be punished.
The 28-minute video of the torture of 13-year-old Rajon raised a wave of protest after it was uploaded in the popular social media, Facebook.
The members of law enforcement agencies also became active to apprehend the perpetrators following the protest raised by people of all walks of life across the country.
The criminals responsible for the murder were arrested by police one after another.
Kamrul, the accused of Rajon's murder was arrested in Jeddah with the help of expatriate Bangladeshis  and  his brother Muhit Alam was arrested following the incident.
Police also arrested Moyna Choukidar, accused of killing Rajon, on Tuesday night, but another accused Ali Haidar is absconding.
Police also arrested Dulal Mia, 30, on Wednesday afternoon with the help of locals from Sheikh Para at Kumargaon.
Beside police arrested Lipi Begum, Muhit's wife and Ismail Hossain, brother-in-law of Muhit.
The charge of the investigation of the case has been handed over to the Detective Branch (DB) of police.