Scientists in Israel say it's easy to "engineer a crime scene" with fabricated DNA evidence, throwing in doubt the strength of the prime standard in criminal cases that has been used to secure thousands of convictions.

The Tel Aviv-based scientists fabricated blood and saliva samples containing DNA from another subject. the New York Times reported. They were able to make the match by accessing a DNA profile in a database without even using any actual tissue or blood from the person they were mimicking,

"You can just engineer a crime scene," said Dan Frumkin, lead author of the study. "Any biology undergraduate could perform this."

It may also be possible to scavenge DNA from a stray hair or discarded cigarette butt and turn it into a saliva sample, a development that has worried the American Civil Liberties Union.

"DNA is a lot easier to plant at a crime scene than fingerprints," Tania Simoncelli, science adviser to the ACLU, told the Times. "We're creating a criminal justice system that is increasingly relying on this technology."

The study, which was published in the journal Forensic Science International: Genetics, can be found online.

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