Don't touch evidence in a terror attack: Expert
Renowned forensic scientist in town to train Singapore police officers
After US president John F. Kennedy was assassinated in 1963, investigators expected the bullet that had hit both him and Texas governor John Connally to have their DNA.
But pathologists made the mistake of washing the recovered bullet, known as Warren Commission Exhibit 399, and other investigators handled the round without gloves.
Renowned forensics specialist Dr Henry Lee, 78, said this complicated investigations into the shooting, which has sparked a host of conspiracy theories.
In an interview with the New Paper, he stressed that civilians should never tamper with potential evidence, including in a terrorist attack.
For example, they should not pick up bullet casings, which are key to helping police confirm the location of the shooter.
The former Taiwan police captain, who moved to the US in 1965, warned: "A mistake can be forever."
Dr Lee, a professor of forensic science at the University of New Haven in Connecticut, is in town until Monday to hold a shooting reconstruction workshop for local police officers.
He last held such a course for the Singapore police in 2006.
A shooting incident on a car was simulated at the Home Team Tactical Centre at Mandai Quarry Road yesterday, after which Dr Lee guided participants to identify bullet casings from three weapons made in different countries.
"Domestic and international terrorists have been switching weapons. In the early days, it used to be bombs, now it is gun shells," he said.
Dr Lee has been involved in more than 8,000 cases, including 9/11 and the murder trial of O.J. Simpson, who was acquitted in 1995.
Dr Lee said shootings can be more challenging to investigate because the police have to work quickly in public spaces.
"You can't close the scene for months, not even for a day."
The public can help, either by becoming witnesses or taking recordings on mobile phones.
While noting that Singapore is safer than the US, he said the Republic must still be on its guard.
He said: "It is really good of the Singapore Police to set this up. You don't wait for something to happen, but you prevent it from happening.
"If something happens, we know how to handle it and how to arrest the perpetrator."