When a body is buried for a long time, it gets skeletonised experts say. In addition, the soft tissues may disintegrate. For this reason, further forensic examination has then to depend on bone injuries, unlike the first autopsy where both soft tissue injuries and bone injuries can be analyzed.
"It is best if the body can be exhumed within a few days for a second autopsy. If soft tissues are destroyed, only bone injuries can be detected. Both types of injuries - soft tissue as well as bone - are vital for forensic examination. Nevertheless, broken bones - like in the jaw and neck - can still be traced and could help to arrive at a decisive conclusion," says Dr Parag Barun Paul, professor of forensic medicine at RG Kar Medical College and Hospital.
Rizwanur Rehman,27, a resident of Kolkata was found dead shortly after his marriage to 23-year old Priyanka Todi, daughter of Ashok Todi, one of Kolkata's richest and most influential businessmen.
Priyanka, decided to marry her Rizwanur, her graphics design tutor, against the wishes of her family.
Yet a month after the two eloped Rizwanur was found murdered near the railway tracks in Dum Dum area of Kolkata on September 21,2007.
It has been alleged that on the behest of Ashok Todi, top police officials threatened Rizwanur with dire consequences unless he divorced Priyanka. It has also been brought to light that on October 2, 2007 Snehashish Ganguly had introduced Ashok Todi to the city Police Commissioner as well as the President of the Cricket Association of Bengal, Prasun Mukherjee.
The CBI inquiry into the matter, which followed a statewide outrage against the incident and the suspension of 5 top police officers, has found incriminating evidence against Ashok Todi. This includes testimonies from two henchmen sent to threaten Rizwanur as well as a hand written note from the couple asking for police protection against Ashok Todi.
According to the forensic experts as Rizwanur's burial took place over 40 days ago there is a high chance of soft tissues being destroyed in this time. As the body is likely to become highly decomposed, bone injuries will be playing a vital role in the second autopsy.
"The chance of the soft tissues getting destroyed is high when a body is exhumed long after burial. Nevertheless, properly detected bone injuries can lead to a conclusive result. Also, the autopsy needs to be conducted in a well-equipped mortuary," informs professor Rabindra Basu, retired head of forensic sciences at NRS Medical College and Hospital.
Basu, who has conducted second autopsies on exhumed bodies, recollects the example of a second post-mortem on a body exhumed six months after burial.
"I got involved in this case around seven years ago. It was conducted on skeletal remains, as the body was exhumed after six months. We could detect the injuries that were of a homicidal nature and the accused was convicted on the basis of the second post-mortem report," says Basu.
Exhumation of the body is done in the presence of a magistrate and the surgeon who conducted the first autopsy.