A Tinton Falls man was sentenced to 41 months in prison for the involuntary manslaughter death of Donald Merce, a principal from Markham Place School in Little Silver.

Dennis Smenktowski, 47, pleaded guilty in 2011 to one count of involuntary manslaughter for driving his car while impaired by the sleep medication Ambien, causing the death of Merce, 58, in a head-on collision, on May 6, 2008, U.S. Attorney Paul J. Fishman announced today. Smentkowski is a retired Long Branch police officer.

According to a release from the United States Attorney's Office, Smentkowski was driving his Ford Explorer southbound on Oceanport Avenue near the east gate of Fort Monmouth at 7 a.m., when he drove across a double yellow line into oncoming traffic and collided head-on with a vehicle driven by Merce, who was on his way to work.

"At the time of the collision with Merce's vehicle, Smentkowski was impaired by the sleep aid drug Zolpidem, a Schedule IV controlled substance, commonly known as Ambien, which he had taken prior to getting into his car," the release states. "Smentkowski admitted he had ingested at least four 12.5 mg dosages of Ambien in the hour or so before the collision, four times the recommended dosage."

"Smentkowski admitted he consciously disregarded the substantial risk to the safety and the lives of others by operating a motor vehicle while his ability to drive was impaired by Ambien," the release continues. "He also admitted his actions caused the death of Merce, who was killed instantly from the injuries he suffered during the collision."

The area around the east gate was a part of Fort Monmouth at the time of the accident, so the site of the collision falls under the exclusive jurisdiction of the federal government. Fort Monmouth closed in 2011, but the federal courts retain jurisdiction over the former Army property.

In addition to the prison term, Judge Pisano sentenced Smentkowski to three years of supervised release.