apparently bunch of drunk kids tried to steal one of the beach boats............cops came and tried to take someone away.......crowd trying to prevent this...............looks like cop just wanted to shoot floor, but hit the kid. As others have said, its kinda normal procedure.
here's the article with more details:
http://www.puertoplatadigital.com/verNoticia.aspx?Id=24471
in short, a group of young people were on a beach with a radio at top volume. CESTUR received complaints about it. apart from the intent to steal the boat that got few men from the group arrested they also tried to disarm the CESTUR officer. in order to calm the raging aggressive crowd he pulled the trigger.