Updated

A former Massachusetts chemist accused of faking test results at a state drug lab has pleaded not guilty to three counts of obstruction of justice at the first of two scheduled arraignments.

Neither Annie Dookhan nor her lawyer commented after her appearance Wednesday in Middlesex Superior Court.

She is scheduled to be arraigned on two more counts of the same charge later Wednesday in Norfolk Superior Court in Dedham.

She had previously pleaded not guilty to similar charges in Suffolk Superior Court, where she was freed on $10,000 bail.

Middlesex prosecutors agreed to let her go on personal recognizance Wednesday.

Prosecutors allege Dookhan fabricated test results and tampered with drug evidence while testing substances in criminal cases. The scandal threatens to unravel thousands of drug convictions.

Dookhan resigned in March.