Retired Army major Sinha Md Rashed Khan had no weapon in his hands when Liakat Ali opened fire on him, confirms the probe carried out by the home ministry's committee.
"Liakat Ali, the in-charge of Baharchhara police investigation centre, shot an unarmed Sinha when the latter had been getting out of his car, obeying the check-post policemen's instructions," said ministry officials quoting the probe report.
The probe body also found that the superintendent of police of Cox's Bazar, ABM Masud Hossain, tried to mislead the killing incident to another direction.
"There was another motive behind the killing of Sinha, and the policemen had ill motives regarding the killing," the investigation report reads.
The probe body also recommended forming an impartial investigation organisation under the home ministry, which will work without police jurisdiction or involvement, said a source related to the investigation.
They also demanded the appropriate usage of government guns and bullets.
The report recommended capital punishment for the main culprit behind the murder, sources with the home ministry and the investigation body said.
It also made a proposal to appoint officers of the rank of assistant superintendent of police to be in charge of remote police stations from now on.
According to a home ministry official, the report submitted to the ministry on Monday made 13 recommendations to prevent the recurrence of such incidents.
A probe committee member, seeking anonymity, told The Business Standard that they found evidence of professional negligence by policemen on the night of the killing as well as after the incident.
The 80-page main report included 586 more pages of statements of the witnesses and 21 pages of photographs.
Home Minister Asaduzzaman Khan Kamal, on Monday, confirmed to reporters he had received the report.
At a press conference, he said the committee was supposed to submit the report within seven working days after the incident, but "we had to extend it several times. However, finally, we have received the full report."
He refused to say much about the report in public because "police are also investigating the case under a court order."
"We will inform the court about what the report contains, and if they want, they can take it [the report] through official procedures," the minister added.
The minister also said the recommendations made in the report will be implemented.
He told reporters that they had not opened the report yet. "After opening it, the home secretary will evaluate it and take necessary actions."
Md Mizanur Rahman, Chattogram additional divisional commissioner and head of the probe committee, handed over the probe report to the minister.
He said, "We were asked to recommend the source and cause of the incident and the remedy. We have submitted this report after thorough analysis."
"The Bangladesh Police is a decorated force, and they are doing an industrious job for the people. I think this lone incident of Teknaf will not tarnish its image overall," he added.
Sinha was killed in a police firing at Shamlapur police check-post at Teknaf's Baharchhara union, on Cox's Bazar's Marine Drive, on July 31, at night.
Sharmin Shahriar Ferdous, Sinha's older sister, filed a case with the Teknaf Senior Judicial Magistrate's Court on August 5.