Her parents left no stone unturned to help her become what she wanted to be: an artist. Sohagi Jahan Tonu had a natural knack for acting, and she would often sing and dance in theater plays.

A good reciter of poems, Tonu used to participate in different cultural competitions and she won many prizes. To realise her dreams, her parents had to sacrifice a lot.

"For many years, I even did not buy a good saree for myself. Because I had to bear all the expenses of my daughter," Tonu's mother Anwara Begum told The Daily Star over the phone yesterday.

But all her dreams are shattered now for good. Tonu's body was found in a bush inside Mainamati Cantonment of Cumilla. The life of the 19-year-old college girl was cut short after she was raped and murdered on March 20 in 2016.

Then a student of Cumilla Victoria College, Tonu took her Honours first year final exams. The results came out after her death. She passed the exams, but she was beyond everything.

"What else I could say other than it was our fate that we lost such a daughter. I could at least console myself if her killers are punished," said the mother in a choked voice.

Five years have passed since the brutal murder that created a stir across the country, but there is no progress in the investigation yet. No one is arrested yet in Tonu murder case.

Yaar Hossain, father of Tonu, first spotted the body of her daughter in a bush on the night of March 20. He filed a murder case the following day against unknown people.

He noticed that the back of Tonu's head was smashed and there were injury marks on her nose. But the police inquest and the first autopsy reports did not mention about the preliminary evidence of the murder.

The first autopsy on Tonu's body had found no evidence that she had been raped before being killed. It also failed to determine the cause of her death.

Following a court order, Tonu's body was exhumed for a fresh autopsy. But it could neither determine the cause of her death nor confirm if she was raped. However, the fresh autopsy found evidence of "intercourse" before death.

Tonu's parents rejected both the autopsy reports, saying those were full of wrong information.

They also alleged that law enforcement officials were trying to cover up the murder and save the killers.

The Tonu murder case is now being investigated by the Police Bureau of Investigation (PBI) since the Police Headquarters transferred the case to the PBI, Dhaka from the Criminal Investigation Department on September 22 last year. The CID handed case documents to the PBI investigation officer Inspector Mozibur Rahman on October 21 last year.

A PBI team visited Cumilla Cantonment on November 15 last year and talked with the victim's parents, said PBI sources.

"We have been investigating the case. We are yet to make any progress," chief of PBI, Deputy Inspector General Banaj Kumar Majumder told The Daily Star on Thursday.

The CID during its investigation for over four and a half years made progress in May 2017 when DNA tests detected spermatozoa of three males on Tonu's clothes.

Assistant Superintendent of Police Jalal Uddin Ahmed, also the CID investigation officer, then said DNA sample matching was going on. The CID never revealed what they found in DNA cross matching.

The victim's family saw a ray of hope for getting justice after CID officials through DNA tests confirmed that Tonu was raped before being murdered.

Following the development, a high level investigation team had quizzed some people at Dhaka Cantonment from October 25 to 27 in 2017.

The CID had claimed to have interrogated more than 200 people, including some army men, but it failed to identify the culprits.

Tonu's mother Anwara said, "I had asked CID officials several times to arrest and quiz Sergeant Zahid and his wife, but in vain. Tonu used to go to their house to give private tuition to their child."

If the couple was quizzed, the mystery surrounding the murder would be unravelled, she claimed.

PBI Inspector Mozibur Rahman, investigation officer of the case, said they visited the place of occurrence and that they were looking into all relevant issues.

Advocate Syed Nurur Rahman, president of Cumilla unit of BLAST, said the Tonu rape and murder case is a sensational one. "We demand a fair probe into the case and highest punishment for those involved."