An off-duty NYPD cop has been arrested for rape, officials said Saturday. Investigators in East Harlem handcuffed police officer Samuel Sierra, 35, around 7:30 p.m. Friday on charges of first-degree rape, strangulation and assault. The NYPD said the attack was “domestic in nature” — meaning Sierra allegedly attacked a partner or family member — but wouldn’t disclose any further details. Sierra’s arraignment in Manhattan Criminal Court was pending Saturday. The six-year member of the force, who earned more than $168,000 last year, joined the NYPD in 2018 and has spent most of his career patrolling the 77th Precinct in Brooklyn. He received a meritorious police duty award in 2019. While on duty in February 2023, he was accused of assaulting a woman and abusing his authority during a traffic stop, according to the 50-a.org website. He was ordered to undergo retraining, although the abuse of authority and physical force allegations were deemed to be “within department guidelines.” In December 2023, he was transferred over to the Auxiliary Police Section, where he helps oversee civilians who volunteer their time as auxiliary cops.