With pressure mounting from families whose loved ones have died at the hands of a police officer, Gov. Andrew M. Cuomo said on Tuesday that he was preparing to issue an executive order naming the state attorney general as a special prosecutor for police-related civilian deaths.

The governor called the order “a major step forward” and stressed his hope that independent investigations would help restore public faith.

“A criminal justice system doesn’t work without trust,” Mr. Cuomo said. “We will be the first state in the country to acknowledge the problem and say we’re going to create an independent prosecutor who does not have that kind of connection with the organized police departments.”

He said that he thought he had assuaged New Yorkers calling for greater oversight of police-related deaths when he announced last month that he was directing Attorney General Eric T. Schneiderman to investigate all such cases over the next year. The governor had pushed for legislation to create an independent monitor to review cases in which unarmed people were killed by officers. But he failed to reach an agreement with legislators before the session ended. As a result, the governor said, he was appointing Mr. Schneiderman by executive action.