The police will use the most advanced technology they have access to - a technology employed in cases of terror blasts - to build a watertight case against the five accused arrested for the gangrape of a 22-year-old photojournalist in Shakti Mills compound, where she had gone with a colleague for a photo shoot.
To employ the 'scene of crime rummaging' technology, the Mumbai police have roped in the Delhi-based Central Forensic Science Laboratory (CFSL) and Gujarat FSL.
On Monday, Mohamed Salim Ansari, 27, who was arrested from Delhi, was produced before court and remanded in police custody till September 5. Ansari is said to have threatened to kill the survivor and raped her first.
Police commissioner Satyapal Singh said they would file the charge sheet as soon as possible, after which the case would be tried in a fast-track court. Singh did not specify a deadline, but crime branch sources said they expect to file the charge sheet in a month's time.
Singh said a team from CFSL and a two-member team from Gujarat FSL arrived in Mumbai on Monday to inspect the scene of crime.
Usually, forensic teams collect evidence that is visible to the naked eye, such as bottles, blood samples, cigarettes, etc., from the crime scene.
"In the crime rummaging technique, officials cover the scene of crime and use a technology that helps them collect the tiniest of particles found on foliage, mud and other things," an officer explained.
"They then search for and extract similar matter from the clothes of the accused and the survivor to prove their presence at the scene," the officer added.
This is used as evidence in court.
R Krishnamurthy, former director of Kalina FSL, said that during her tenure as FSL director this technology was used once in a terrorism case. "This technology is usually employed to trace chemicals in explosives," said another expert, requesting anonymity as he is not authorised to speak to the media.
A police officer said the passage of time would not contaminate the scene, but a forensic expert said he doubts the teams will find anything as four days have passed since the crime took place at Shakti Mill.