McCullagh's retirement is effective Friday, April 23.
He will be replaced by Captain Jeff Wanamaker, who will serve as interim chief until a new chief is named, said Clarkstown Supervisor George Hoehmann.
McCullagh worked his way up through the ranks of the department from patrol officer, investigator, patrol sergeant, special operations sergeant, patrol lieutenant, to administrative lieutenant and was a member of the Rockland County Narcotics Task Force and the Town's Critical Incident Response Team.
He is a graduate of LaSalle University and attended the FBI National Academy.
"When Chief McCullagh took on the responsibility of commanding this department, he reminded us all that leadership is about supporting and empowering people," said Hoehmann. "The effort you have put into building a positive and professional relationship between our department and the community we all so proudly serve will last well into the future. We thank you for your service and we hope you enjoy a long-deserved retirement."
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