Rab members also presented two members of the gang before newsmen at a press conference held at the office of Rab-2 in the city yesterday.

The arrested killers confessed to their involvement in at least ten murders each, including that murder in Narsingdi on May 19.

The law enforcers also claimed to have captured the gang leader who reportedly murdered about 52 people in separate incidents of homicide across the country.

But the elite force members denied giving further information about the leader as the investigation is being conducted in a wider range to capture all the gang members.

The arrestees, identified as Akhtaruzzaman Biru, Dudh Miah, Khokan and Zillur Rahman alias Zillur said that they committed robbery in the house in Bhelanagar area in Narsingdi on information that they would find Tk 10 lakh in the house.

Rab arrested them from Bhairab and Kishoreganj on Wednesday and recovered the sly range used in cutting grill of the house and a cellphone from their possession.

As Biru depicted the killing, on information by a local, the gang with six-member went to the house at around 1:00am on May 19.

Dudh Miah set the plan for the attack negotiating with Biru in Bhairab the previous day.

Putting four members outside, two of the killers entered the house by cutting window grills and at first killed Razib by hitting him with a rod. Then another three entered the house leaving one outside as a watchman.

Two of them inside searched for the money. They did not find any money and like their previous manner went on killing all the family members by hitting them with rod. They also raped two youths before killing them.

The robbers fled the scene taking only a cellphone from the house that led the law enforcers to know about Biru at first and later to capture the rest.

The law enforcers did not find involvement of any relatives of the ill-fated family to the incident.

After giving a list of nine cases involving 20 killing against the gang, the law enforcers told the press that each incident of crime by the gang is distinctive and identical to each other. They never left behind a single person alive and killed everyone who came along during the robbery. And for this reason the gang could not be traced due to lack of witness and proper evidence. They liked to kill people by lethal weapon rather than using firearms.

Commanding Officer of Rab-2 Additional Deputy Inspector General of Police M Akbar Ali told the Daily Star "No investigation cases could be filed against this gang as they never left behind any clue. There are 18 to 20 more cases against the gang".

Police recovered six decomposed bodies of the family from inside their residence in Bhelanagar on May 22.

The victims are Rais Uddin, 52, his wife Salma Begum, 46, their son Rajib and daughters Yuona, 28, Swarna, 18 and niece Urmi, 8, who was also adopted as a daughter.