Patrick Lynch, head of the New York City police union, unleashed a pointed letter on Tuesday, addressed to what he called “arm-chair judges” of the NYPD’s misidentifying, tackling, detaining and handcuffing of former tennis star James Blake. Security camera footage of the incident revealed Blake leaning against a pillar and scrolling through his phone in front of his Manhattan hotel last week when a plainclothes cop barreled towards him, grabbed him forcefully by the shoulders, spun him around and slammed him onto the ground.