I don't think we want a federal police force capable of monitoring closely the actions of ten million people, even if technology would allow such a thing.
If we don't instill discipline and self-control in our children by about age three, it is unlikely that we will ever be free from attacks like the one in Florida.
The best we can hope for is to reduce the carnage when such people strike. The number of people harmed in such attacks probably numbers in the low hundreds at most. This problem is far from the most serious that our nation faces and should not be used to justify modifying the Bill of Rights.
If the knee-jerk liberals calling for more gun control were serious about reducing loss of life they would be focussing on s-holes like Chicago.
It seems that most all of these mass shootings, or attempts,are by whites who have known mental health issues. Many, if not most, have been on prescribed psychiatric drugs yet legally buy weapons. IMO we have a national mental health problem and these killings are the product of it.