A News 12 investigative report shows the number of driving while intoxicated arrests in Nassau County has dropped by almost 1,500 over the past six years.

Nassau PBA President James Carver says the reason for the dip is clear. He blames the drop on a 2011 departmental decision to disband the Safety Enforcement Team, or SET, in Nassau. The SET team's specific purpose was to enforce drunken driving laws. In 2010, the year before the unit was eliminated, Nassau police made 2,648 DWI arrests. Since that time, that number has dropped by 42 percent.

The amount of DWI arrests is up by 4 percent since 2010 in Suffolk County, where the department still maintains its SET team.

"When you have a dedicated team, their numbers are going to be much higher. Their enforcement is going to be much better," Carver told News 12.

Acting Nassau Police Commissioner Thomas Krumpter insists the disbanding of SET was not a cost-saving measure. He says the money was diverted toward targeted patrols.

"We attribute [the drop in arrests] to a higher degree of compliance in Nassau County," says Krumpter.

Krumpter points to the fact there were 24 fatal accidents attributed to DWI incidents in Nassau last year, which he says is the second lowest total in 30 years. However, the percentage drop in fatal accidents still pales in comparison to the dip in arrests.

"If someone were to tell me that there are less drunk drivers on the roads, I just wouldn't believe that," said Marge Lee, president of DEDICATEDD - a nonprofit organization that advocates for the victims of drunken driving.

Nassau District Attorney Kathleen Rice released a statement to News 12 saying, "We've raised serious concerns to the police department about the day-to-day enforcement of drunken driving laws...We don't control how another agency uses its resources."