Mourners cram together on the sidewalk to listen to the funeral service for New York Police Department officer Wenjian Liu in the Brooklyn borough of New York January 4, 2015. Liu, 32, and Rafael Ramos, 40, were shot to death on December 20 as they sat in their squad car in Brooklyn. Their killer, Ismaaiyl Brinsley, who killed himself soon after, had said he was seeking to avenge the deaths this summer of two unarmed black men at the hands of white police officers. REUTERS/Mike Segar (UNITED STATES - Tags: CRIME LAW OBITUARY)