Investigators from the New York Police Department (NYPD) were observed in Central Park on Saturday, as the department continues searching for evidence from the Dec. 4 killing of Brian Thompson. (Christina Coulter / Fox News Digital) Investigators from the New York Police Department (NYPD) were observed in Central Park on Saturday, as the department continues searching for evidence from the Dec. 4 killing of Brian Thompson. (Christina Coulter / Fox News Digital)