Rab yesterday arrested the prime accused in the murder of teenage boy Sagor Mia in Kishoreganj's Bhairab upazila.
The arrestee is Akkas Ali, 45, of Charsirampur village in Mymensingh Gouripur upazila.
On information, a team of Rab-14, led by its special company commander and additional superintendent of police Sajjad Hossain, raided Shambhupur area around 3:00am and arrested Akkas, Rab sources said.
Akkas was waiting near Shambhupur rail crossing in Bhairab for a Sylhet-bound train to escape arrest, the sources added.
Rab later handed over Akkas to the Detective Branch of police in Mymensingh, which is investigating the case.
On Monday morning, Akkas and his associates beat Sagor to death over an allegation that the 18-year-old attempted to steal a water pump from Akkas' fish hatchery at Charsirampur in Mymensingh's Gouripur.
Sagor, son of Shipon Mia of Natokghar Lane Railway Colony area in Mymensingh town, came out of house around 4:00am with a rickshaw-van to collect scrap, family members said.
The attackers beat up Sagor after tying his hands to a concrete pillar. At one stage of beating, Sagor crumpled to the ground and they untied his hands and left the place with him in a CNG-run auto-rickshaw, saying that they were taking him to a hospital, said witnesses.
But the victim was never taken to hospital, and his body was dumped into a bush adjacent to the hatchery sometime later.
On information, police recovered the body. After the incident, Akkas and his men went into hiding.
On Tuesday, victim's father Shipon filed a case against 12 people with Gouripur Police Station, naming six of them. They are Akkas, his brothers Hashu Mia, Abdus Sattar Chhuto, Jewel Mia and Sohel Mia and his employee Qaiyum.
The case was later transferred to the DB.
Earlier, police arrested Reaz Uddin, 50, and Fazlur Rahman, 50, of the same village, for their alleged involvement in the incident, said Delwar Ahmed, officer-in-charge of the police station.
They were produced before a Mymensingh court that sent them to jail later, added the police official.
Drives are on to arrest the other accused, said the OC.
Locals and different organisations are demanding the arrest of all the culprits and exemplary punishment for them.