I wonder if he actually fired into the ground, or into the air. They said they found the shell casing, but didn't say anything about finding torn-up turf, or a hole in the ground. I doubt that much will come of this if the round actually went into the ground, however, they might want to make an issue of it if fired into the air. That round would have to come down somewhere.
In any case, it's a class B misdemeanor, punishable by a maximum fine of $2000, max jail term of 180 days (Yikes! 6 months), or both.
And it is not a good idea to lie to police. You never know what somebody may have seen or heard, including the miscreants that were causing the problems in the first place -- they'd be witnesses, too. Keeping quiet is one thing, lying is a whole different animal. (My understanding is that It is NOT illegal for the police to lie to a suspect.)