As the city marked another year without him, the Dallas Police Department paid tribute yesterday to the legacy of Officer Johnny Sides, a patrolman taken too soon amid the line of duty’s unrelenting call. Sides, who was only 22 when his watch ended due to an egregious act of violence, was memorialized in a social media post that echoed the loss felt by the department and the community he served. The remembrance reverberated across the city as a reminder of the cost of public service, according to the Dallas Police Department.