Rockland County’s newest district attorney was officially sworn into office Thursday.

Thomas Walsh took his oath of office at a ceremony at the Rockland County offices.

His term officially began three weeks ago and comes at a critical time for law enforcement.

The former Supreme Court judge is now forced to deal with the first year of the state's criminal justice reform laws, including quicker requirements to turn over evidence and releasing more people without bail.

Walsh is also dealing with one of the country's most high-profile cases, with the arrest of Grafton Thomas in the Monsey Hanukkah stabbing attack.