Can Touch DNA solve Aarushi murder case?

With the CBI closure of the Aarushi Talwar murder case evoking anger of the victim’s family and friends, the teenager’s parents feel that the ‘Touch DNA’ testing could have solved the mystery.

The CBI has said in a Ghaziabad court on Wednesday that despite two years of investigation, it cannot solve the murder of 14-year-old Aarushi Talwar, and her family’s domestic help, Hemraj.

“I had researched a lot about this test – Touch DNA -and asked CBI more than a-year-and-a-half ago to get it done.
“But they did not. The test could have revealed who was there in the room that night [of Aarushi?s murder]. The test has helped solve a lot of cases,? Aarushi’s father Rajesh Talwar told reporters, outraged by the closure of the case on Thursday.
The touch DNA method, which analyses skin cells left behind when assailants touch victims, weapons or something else at a crime scene, has been around for the last five years.

The technique has dramatically increased the number of items of evidence that can be used for DNA detection, according to US medical journals like Scientific American.

In the 1980s, in order to perform DNA analysis on a crime scene or victim, forensic investigators needed a blood or semen stain about the size of a quarter. The sample size fell in the 1990s to the size of a dime and then became: ?If you can see it, you can analyze it.?

Touch DNA testing only requires seven or eight cells from the outermost layer of our skin.

Investigators recover cells from the scene, then use a process called Polymerase Chain Reaction (PCR) to make lots of copies of the genes. Subsequently, scientists mix in fluorescent compounds that attach themselves to 13 specific locations on the DNA and give a highly specific genetic portrait of that person.

The whole process takes a few days, and forensic labs are often backed up analysing data from other cases.

In the US, the touch DNA method had been able to solve the controversial case of JonBenet Ramsey’s family death case triggering requests for the test from law enforcement officials seeking similar breakthroughs in unsolved crimes.

Meanwhile, Nupur Talwar, Aarushi’s mother, said she is heart-broken by the closure.

“I am shocked. I had huge hopes pinned on the CBI…this is not something I can deal with or bear,” she said.

?I don?t know why CBI is behaving like this,? she said.

The CBI earlier suspected that Aarushi had been killed by three men: Krishna, who worked in Rajesh Talwar’s clinic; Rajkumar, who worked for the Duranis, close family friends of the Talwars; and Vijay Mandal, who worked for a family that lived in the same apartment block as the Talwars.

The three men were arrested and put through narco-analysis, but their tests did not lead the CBI to any breakthroughs.

They were eventually released after the CBI admitted that it had no evidence against them.