Can someone explain to me what the statement in bold means?

http://www.nydailynews.com/front/story/354992p-302463c.html

The city scientist who led the effort to identify 9/11 victims said officials made sure to keep the remains of the three terrorists identified away from those of the innocents killed.

The remains of the killers were removed from the medical examiner's makeshift memorial park on the East Side and "put in another place," Robert Shaler, former head of the medical examiner's forensic unit, told the Daily News.

In "Who They Were," his new inside account of the identification effort, Shaler writes that he believes the terrorists identified were in the back of the planes - and not the monsters who plowed the jets into the towers.

"I still doubt the pilots have anything remaining to collect or analyze," he writes. "Likely, they were vaporized along with many of the innocent victims."

Shaler recounts with fresh detail the scientific challenge and personal anguish that marked the more than three years it took to process the bodies and 20,000 body parts recovered from Ground Zero.

Though the remains of 1,594 of the 2,749 WTC victims have so far been identified by name, Shaler makes clear the terrorists were a case apart.

To begin with, Shaler's office could not identify the three by name. That's because the 10 DNA profiles used to make the first matches were supplied by the FBI without names attached.

"No names, just a K code, which is how the FBI designates 'knowns,' or specimens it knows the origins of," Shaler wrote. "Of course, we had no direct knowledge of how the FBI obtained the terrorists' DNA."

Terrorist remains were separated from the others, to allay families' concern that the killers might someday be commingled with the unidentified remnants of their victims, due to rest at the Trade Center site. Shaler said he didn't know where the terrorists' remains are now but assumed they are kept somewhere in the city.

"We didn't say where we put the terrorists' remains because it's not important," the medical examiner's spokeswoman, Ellen Borakove, said yesterday, adding she did not know the location herself.