This will contain some spoilers for early season 2 episodes.
In episode 3 (New York's Finest), in this
awesome fight sequence, we see Daredevil place an unconscious Frank Castle in a freight elevator heading for the first floor as he disembarks to take care of the Dogs of Hell in the building. Daredevil manages to make it to the first floor before the elevator does, and at one point we can clearly see that Castle is still unconscious when the elevator doors open. After defeating the last of the Dogs of Hell, we can hear police sirens in the distance. But, in the beginning of the next episode, Frank Castle is still walking free. There's no indication that he's been in jail or police custody, and given his crimes, I doubt that he'd be free to make bail. So why didn't Daredevil turn him over to the police after defeating the Dogs of Hell? I don't recall any indication during this or the next episode that Castle regained consciousness and ran off, and Daredevil certainly wasn't happy with him considering what happened with Grotto.