By Michael Levenson and John R. Ellement Globe Staff

Governor Deval Patrick said today that David Meier, a former Suffolk County homicide prosecutor now in private practice, will lead the central office set up to review thousands of criminal cases potentially tainted by the mishandling of drug evidence in a state lab.

Patrick said Meier, a partner at Todd & Weld in Boston, will oversee officials from a range of state and federal agencies as well as defense attorneys and prosecutors who will sift through the 34,000 criminal cases that may have been jeopardized in the scandal at the now-shuttered Department of Public Health lab in Jamaica Plain.

“The job of the office is to make sure no one falls through the cracks,” Patrick said in a press conference with Meier outside the governor’s office.

Meier said he would approach the daunting task not as a prosecutor, defense attorney, or judge but “as an advocate for fairness and due process on behalf of the criminal justice system.”

The process has the potential to result in the early release of an undetermined number of prisoners. In two early cases of fallout from the lab scandal, two men convicted in drug cases walked free from Norfolk Superior Court today.

Also today, the attorney general’s office today said it would conduct a “broader investigation” of the drug analysis unit of the lab. That review will focus on cases beyond those handled directly by the chemist now at the epicenter of the case and will involve the hiring of independent forensic experts to guide the inquiry.

A top aide to Coakley said in letter to the Massachusetts District Attorneys Association and the Committee for Public Counsel Services, the public defender agency, “Our review is focused on whether any failures at the laboratory impacted the reliability of the results on cases beyond those handled directly by the chemist.”