On May 16, the double murder of teenager Aarushi Talwar and domestic help Hemraj that shocked India will be four years old. But the question - whodunit - is still as much of a mystery, with the first hearing in the trial held just last week in a court in Ghaziabad.
There have been twists and turns aplenty, with the Central Bureau of Investigation (CBI) accusing Aarushi's dentist couple parents Rajesh and Nupur Talwar only in February 2011, the first formal order in the case. The circumstantial evidence against them was that they were the only people present at the crime scene.
Aarushi, 14, was found with her throat slit at her home at Jalvayu Vihar in Noida on the outskirts of the capital on May 16, 2008. The body of her family's domestic help Hemraj, who was initially suspected for the crime, was found the next day on the terrace of the house.
CBI investigators, who took over from Noida police, claimed that 90% of the evidence had been destroyed.
Though there was a whiskey bottle in Rajesh Talwar's room and two bottles in Hemraj's room on the terrace, the fingerprints could not be matched.
"Apart from not capturing the finger prints on whiskey bottles in Hemraj's room, police allowed the media to freely roam around the crime scene rather than restricting access to the flat," a source in CBI said.
In addition, police allowed doctors not specifically trained in forensic pathology to conduct the autopsies of Hemraj and Aarushi, he said.
While it is established procedure to lift fingerprints from the skin of victims, doctors entrusted with the autopsies neglected to call forensic scientists for the job, the sources said.
Experts at the All India Institute of Medical Sciences (AIIMS) have raised questions over one entry in Arushi's postmortem report in which whitish discharge was mentioned from the vagina but not investigated.
"In this case no further investigation was done on the evidence that investigators got from natural orifices. The report doesn't mention whether a vaginal swab was sent for further investigation," Sudhir Gupta, associate professor, forensic medicine, AIIMS, said.
As things stand today, Nupur Talwar is in judicial custody in Ghaziabad's Dasna jail and fighting to get bail, while standing trial. The trial began only on May 11, almost four years after the crime.
Nupur Talwar's husband and Aarushi's father, Rajesh Talwar, is out on bail. He was arrested and kept behind bars for 50 days before being set free in July 2008. He was then made an accused three years later.
The most dramatic turn in the case, perhaps, came when a magistrate in Ghaziabad rejected the CBI's request to close the case and held that there were enough grounds to proceed against the teenager's parents.
After taking up the probe June 1, 2008, and following multiple leads, the CBI filed the closure report in December 2010.
The CBI put the ball in the magistrate's court on the issue of proceeding with the case or burying it as one which had reached a dead end.
Before the Talwars were named, police had picked up three others -- Krishna, the Talwars' medical assistant; Raj Kumar, a domestic help with a family friend of the Talwars; and Vijay Mandal, another domestic help in the neighbourhood.
However, they were let off on bail because the CBI couldn't prove its claim due to lack of evidence.
After four years, the action now has shifted to the trial court in Ghaziabad. As the prosecution and defence fight it out before Judge S Lal, Aarushi's friends and family are hoping that the "real culprits" don't go scott free.
Majid Memon, a criminal lawyer, said, "As Aarushi's body was cleaned and most of the evidences was tampered with, her parents are the accused as per the circumstantial evidence.
"First, Uttar Pradesh Police did not take proper care of the evidence and later CBI also showed lazy attitude in the case.”
Nupur Talwar's lawyer Praveen Rai said: "We have demanded a CD and other related documents from the CBI... The court has ordered CBI to submit all the documents on May 15.”
Interestingly, the hearing in the case has been adjourned to May 16 -- when it will be exactly four years to the murders.