Adam Lanza was quiet and socially
awkward. There are too many quiet and socially
awkward people in the world, male and female, to make identifying the next Adam Lanza a realistic priority. The one person that could have set the
kid free (himself, to free himself from himself) failed to act, failed to tell anyone about who he was, so instead he decided to show the world something else, to take the freedoms and lives of many people in the process.
There are a lot of people with the personality similar to Adam Lanza that never take a life, so trying to give people information about his personality and hope they they
will produce another Adam Lanza for you before the act (like Minority Report) is silliness. Everyone is part of the problem, but the
kid had to be
the one to do the work on himself, not every other person doing the work on him for him.