As Superintendent, Constantine instituted vigorous enforcement programs targeting drunk drivers who were responsible for a majority of the fatal accidents in the state.

Concerned about the impact of violent crime, Constantine instituted the NYSP Forensic Unit, the first of its kind by a domestic law enforcement agency.

This program, based in state police headquarters, provided immediate resource support to local law enforcement authorities confronted with suspicious or unsolved murders and violent assaults.

Specially trained state police homicide investigators successfully solved a series of serial killer incidents in Rochester, Long Island, Utica, and the Catskill area in the 1990s.

Four regional teams of undercover troopers were established in upstate New York to assist local agencies confront drug dealers.

Constantine's performance caught the attention of Attorney General Janet Reno and FBI Director Louis Freeh.

In this capacity, he focused enforcement efforts against the powerful international organized crime groups that control most of the drug trafficking in the United States and throughout the world.

In order to provide more assets to the field operational units, the headquarters decision-making and staffing levels were reduced with an emphasis on decentralized authority.

Beginning in 1985, when Constantine was Field Commander of the New York State Police, he oversaw an effort to expose and dismantle what has been acknowledged to have been the largest and most powerful criminal conspiracy in history.

On January 5, 1996, Constantine established the DEA Purple Heart Award to honor individuals who had lost their lives or been seriously injured enforcing the drug laws of the United States.

In May 2000, Constantine was appointed by the British Government to serve as Oversight Commissioner for a major reform of provincial policing in Northern Ireland.

Pursuant to the Good Friday agreement of 1998, a commission chaired by former Hong Kong Governor Chris Patten had issued a plan for the reconstitution and reorganization of the Royal Ulster Constabulary into a new Police Service of Northern Ireland.