A Brooklyn man was arraigned Thursday for allegedly building a bomb in his East Flatbush home and killing a man with it in Queens.

Victor Kingsley, 37, is charged with using a weapon of mass destruction. Prosecutors say he targeted an NYPD officer last July with a package laced with explosives, but he got the wrong address and wound up killing 73-year-old George Wray. His widow was seen leaving the arraignment.

Officials say it was part of a revenge plot for an arrest three years ago.

A day after arriving at Kingsley's 43rd Street home, investigators were still on scene Thursday, combing through what they described as bomb-making materials. The bomb squad and FBI confiscated material that needed to be taken away in an armored vehicle.

If convicted, Kingsley faces up to life in prison.