Do sketches of suspects help in terror probe?

The team investigating the Mumbai serial blasts, which claimed 19 lives on July 13, has pinned a lot of hope on the sketch of a suspect. But rarely is a suspect arrested on the basis of a sketch.

The police were quick to draw up sketches of suspects after the serial blasts in Delhi, Hyderabad, Bengaluru, Jaipur and Ajmer in 2008. While in some cases the suspect was never found, in other instances the police always managed to pick up the wrong person.

While probing the attack on the IISC, the police never found the person in the sketch. In the case of the twin blasts in Hyderabad twin blasts, the police detained a person on the basis of a sketch but he turned out to be innocent.

The success rate of arresting culprits based on their sketches is less than one per cent, says an officer in the Bengaluru police.

"Sketches are based on human memory and it is based on some one else's description. In my experience it is never found to be useful; it appears more of an exercise to satisfy people," he said.

"How can you expect a passer-by to describe the face of a terrorist who they must have seen for the first time, that too for a few minutes," he pointed out.

"The only time a person is found based on a sketch is if the accused has an earlier police record, with a photograph," said the official.

Sketches are prepared on reasonable suspicion of a person. A face is divided into multiple component parts like the eyes, the chin etc.

A major problem with this line of investigation is that terror outfits never repeat a foot soldier to carry out operations. They usually deploy new operatives to carry out terror strikes to avoid detection.

In case the terrorist is wearing googles, a wig or sports a beard, the task of drawing an accurate sketch becomes near impossible as most of his facial features are hidden.

Experts believe that instead of relying on sketches of suspects, more CCTVs should be installed in public places. Only 0.3 per cent of India's total area is covered by CCTVs and they often have poor resolution.