[6] Singas served as acting Nassau DA starting in January 2015, assuming the role following Rice's election to Congress.

Upon taking office, Singas became the first Greek-American and the second woman to become the top law enforcement official of Nassau County.

The Task Force is chaired by Deputy Executive Assistant District Attorney for Community Relations, Joyce Smith.

Working with the Unified Court System, she volunteered her office to lead a pilot program that served as a precursor to the state's “Raise the Age” law.

She was an advocate for eliminating cash bail, and replacing it with a validated risk assessment tool, writing in 2019 with Suffolk County District Attorney Timothy Sini in Newsday, “We need to overhaul New York’s bail system because no one should be in jail awaiting trial simply because they’re poor.

New Yorkers deserve comprehensive criminal justice reform this year that enhances fairness..."[11] In 2020, she joined fellow District Attorneys Darcel D. Clark, Eric Gonzalez, Melinda Katz, Michael E. McMahon, Anthony A. Scarpino Jr., and Cyrus R. Vance Jr. calling for further reforms, and reiterating the call to eliminate cash bail, in an op-ed in The New York Times.

On April 3, 2018, Singas appeared at a rally and spoke before an audience of about 200 people at Temple Beth Israel, a synagogue in Port Washington, New York, advocating in favor of what she described as common sense gun legislation.

"[17] Singas was the defendant in a federal constitutional case, Maloney v. Singas (formerly Maloney v. Rice[18]), in which the plaintiff is seeking a declaration that he has a constitutional right to possess nunchaku, a martial-arts weapon, in his home for peaceful martial-arts practice and home defense.

[20] On May 25, 2021, governor Andrew Cuomo announced that he would nominate Singas to serve as an associate judge of the New York Court of Appeals, replacing Leslie Stein.