"Earlier today, we lost one of our Finest in a suicide bombing in Bagram, Afghanistan," Police Commissioner Bill Bratton said in a statement.
"Detective Joseph Lemm epitomized the selflessness we can only strive for: putting his country and city first."
Lemm was promoted to detective in January 2014 and served in the Bronx Warrant Squad. He was deployed three times -- twice to Afghanistan and once to Iraq, Bratton said.
"Tonight, we grieve and we remember this selfless public servant who dedicated his life to protecting others," Bratton said.
In addition to those killed, two American service members and a contractor were injured during a patrol outside Bagram Air Base.
"It is with deep regret that I learned today that six U.S. service members died in Afghanistan Monday," Defense Secretary Ash Carter said in a statement. Carter. "We are still learning all of the details, but two other service members and a U.S. contractor were also injured. They died after a vehicle-borne improvised explosive device attack on their patrol outside Bagram Air Base. It serves as a painful reminder of the dangers our troops face every day in Afghanistan."
Bagram houses the majority of the 9,800 troops in Afghanistan, part of Operation Resolute Support, in place to train and assist Afghan military forces.