Detective Branch Sub-Inspector Swapon Kumar Sarkar submitted a report to the Chief Metropolitan Magistrates Court of Chattogram on Sunday after four and a half months of investigation.
“After analysing the circumstances, post-mortem examination and viscera reports, and statements of 16 witnesses, we are certain that she died by suicide,” DB Additional Deputy Commissioner Abu Bakr Siddique told bdnews24.com.
Abu Bakr also said they also found nothing suspicious in forensics and DNA test that led tolhem to conclude that the girl, Tasfia Amin, killed herself.
The investigation report, however, does not mention specific reasons behind the ‘suicide’.
Police recovered Tasfia’s body from the pier no. 18 at Patenga on May 2. Her family identified her later from photos of the body posted on Facebook.
Tasfia, a grade nine student of Sunshine Grammar School, an English-medium institution in the port city, went out with her boyfriend to a restaurant in the evening of May 1.
The case was transferred to the Detective Branch on July 7.
Police said CCTV footage of the restaurant showed Tasfia and her boyfriend had left it by separate autorickshaws.
Shopkeepers near the scene where the body was discovered said they had seen Tasfia walk along the river bank and heard someone cry sometime later, DB official Abu Bakr said.
The shopkeepers also went searching for her at the time but found nothing, the detective added.
Police had also looked for the autorickshaw that Tasfia took after she had left the restaurant but could not find it as they failed to get the registration number.