A security weakness in the technology used by most of the crime labs in the US to analyze DNA evidence exposed 30 years of crime files to the risk of being hacked, according to a group of forensic and computer scientists, The Wall Street Journal reports.

The researchers found that with the help of computer code written by widely available AI software, they could alter the data produced from computerized scans of physical DNA evidence without leaving any trace they had tampered with the records. The vulnerability is likely to have existed in the digital files produced by crime-lab machines since 1995, but recent technological advances make potential tampering much easier now, they said.

Thermo Fisher Scientific, a data security company, has acknowledged the vulnerability and announced that it is working with the US Cybersecurity and Infrastructure Security Agency to resolve the issue.