BOSTON — David Danielli was allowed to withdraw his guilty plea after it was discovered that state chemist Annie Dookhan had tested the evidence used to convict him.

BOSTON — The outgoing head of the state’s public health department says he believes a “single rogue chemist” was responsible for the mishandling of drug evidence.

BOSTON — State lawmakers are looking to hold hearings as early as next Wednesday to try to get to the bottom of what happened at the state’s drug lab.

BOSTON — John Auerbach accepted blame for the failure to monitor, detect and report the mishandling of drug samples by a single state chemist.

BOSTON — The drug evidence mishandling scandal at the state crime lab in Jamaica Plain has led to the resignation of Commissioner John Auerbach.

STATE HOUSE — Department of Public Health Commissioner John Auerbach offered his resignation over the weekend and Gov. Deval Patrick accepted it on Monday.

BOSTON — One employee has been fired, another has resigned, and a third faces disciplinary proceedings as a result of an investigation.

BOSTON — A chemist whose alleged mishandling of drug samples led police to shut down a crime lab testified in 2010 that she was in charge of quality control at the lab.

BOSTON — State agencies and district attorneys on Wednesday will to try and clarify what happened at the troubled state crime lab that was shut down last month.

BOSTON — Gov. Deval Patrick is urging prosecutors, defense attorneys and state departments to join forces to determine which potentially mishandled samples at a state lab pertain to people now behind bars.

BOSTON — Gov. Deval Patrick is predicting “consequences” for what he calls a “breakdown in oversight” at a now-closed state crime lab.

BOSTON — The new revelation raises the possibility of an enormous number of legal challenges from people convicted or awaiting trial in drug cases.

BOSTON — State officials have suspended two supervisors at a Massachusetts crime lab where a chemist is accused of mishandling drug evidence.

BOSTON — Officials are investigating allegations of deliberate mishandling of evidence by a woman who had worked for the lab for 10 years.

BOSTON — State police discovered a chemist failed to follow protocols in drug testing, potentially exposing thousands of drug convictions to legal challenges.