The Buffalo Bills are going to wait a good, long while before deciding what to do with LeSean McCoy as his legal situation unfolds. We know this for two reasons: they said that's what they're going to do, and we've also seen it in practice.
On July 12, 2015, Bills offensive line coach Aaron Kromer was arrested and charged with misdemeanor battery against two minors. The incident apparently came about because of an argument over beach chairs. Punches were thrown and, per the initial police report, a death threat was made.
The Bills' only move at that time was to put Kromer on indefinite paid administrative leave, in accordance with the NFL's personal conduct policy, until the legal situation was resolved. For weeks, fans and media types alike speculated that the Bills would be firing their offensive line coach before he even coached a game for them.
On July 31, 2015 - 19 days after the initial reports came about - the charges against Kromer and his son, Zachery, were dismissed. The parents of the minors dropped the charges after an amicable settlement was reached, and in part because the minors did not sustain serious injuries that required medical treatment. Two days later, on August 2, the Bills handed Kromer a six-game suspension. The next night, he was coaching at training camp. He coached throughout the preseason, served his suspension when the regular season began, and then he coached the offensive line for the final 10 games of the season. He'll return as the Bills' offensive line coach next season.
McCoy's ongoing case is not, of course, the same case. He still has not been arrested or charged (though that obviously may change), the complainants in this case were adults, and the injuries here are much more severe, requiring hospitalization. The clearest parallel between the two cases, at present, is that the incidents were generated by an argument over something silly; beach chairs and champagne are not things to be throwing haymakers over, friends.
But even though the situation is not precisely the same (and it's highly unlikely that it'll be over with in under three weeks, as well), the Bills' approach will be: they'll wait for everything to play out, and to gather as much information as possible (and possibly for some sort of legal resolution), before making any final decisions, one way or the other.