When Jessica takes Ruben's severed head to the police station, it's the same precinct that Matt Murdock frequents in Daredevil (it makes sense, it's the same neighbourhood, after all). That means the same picture of Stan Lee is still on the wall in the background (though it's very much a blink-and-youll-miss-it moment). The desk cop also ports over from Daredevil: having appeared in 6 episodes of the first Netflix show, Royce Johnson reappears as Sgt Brett Mahoney for a cameo, tying the two shows together. It seems he survived the inevitable Serpico style death he predicted in Daredevil then. The same police station has a clipping of Ben Urich's investigative journalism work that got him killed in Daredevil...
