New York Police Officer Jason Rivera was no stranger to the tensions between police and some communities. He'd seen it up close, growing up in his heavily Dominican neighborhood in northern Manhattan. And it was personal, like when he saw his brother get pulled from a taxi and frisked. His partner, Wilbert Mora, knew it from his youth in East Harlem. He spent his college years thinking about ways to address it. But their lives ended in gunfire in a Harlem apartment, responding to a domestic disturbance last week. Rivera, 22, had been a police officer for barely a year. Mora, 27, was in his fourth year on the job. Rivera's casket, draped in a green, white and blue NYPD flag, was carried into St. Patrick's Cathedral on Thursday for his wake. Cardinal Timothy Dolan will preside over his funeral Mass there on Friday.