A Modest Proposal

The main reasons schools are targeted is it is assumed that you won’t meet armed resistance there, there is a multitude of targets there, the people that a troubled young person is most likely to have a grudge with are there, and the press coverage will be assured.
Here is a solution set;
1. Relocate police precincts and Sheriff’s offices in schools so they share the same building. Redistribute all existing law enforcement. Police should work out of the school buildings exclusively. Kids will grow up with them there everyday.
2. Hire and train additional veterans as sworn law enforcement officers to cover all schools in the district.
3. Cover all school zones and crosswalks to schools with the assigned law enforcement officer every morning and every afternoon. There is no more important place to be everyday.
4. Change policies and practices so that police only respond to calls, they no longer patrol on a regular basis. There is no data showing that patrolling reduces crime at all.
5. Pass a nationwide bill that makes it illegal to publish the name of a person suspected of a school shooting, or any terrorist act, or the details of the attack. This removes the incentive.
6. Implement programs and culture in schools to reward bravery, courage, and self-sacrifice to those who stand up for the less fortunate and protect those being bullied. It needs to be the culture that when students see someone being picked on, THEY step in, several students. They don’t go to an adult, and schools need to encourage and reward this.
7. The entire mental health care system needs to be nationalized and free to everyone. Every facet of it; from medication, to therapies, inpatient care, and life-long care.

The reason entertainment venues are chosen is for similar reasons; the shooter is least likely to meet resistance because these facilities screen for weapons at the door, there is a large number of targets in a small space, and press coverage is extremely likely.  Like the school shooting problem, the solution is multi-faceted and required several things done simultaneously.
In addition to all the measures above for schools, here also is a solution set:
1. Allow concealed carriers with valid permits and ID to enter with firearm.
2. Require professional security for certain size venues. Armed and trained.  Not on duty for any other reasons; i.e. bouncing drunks etc.
3. The random nature of these events, and inability to total secure this type of venue leads to best defense is a good offense.  The type of measures and the venues need to be offensive in nature ensuring that it is no longer a soft target.
4.  The best measure against active shooters is actively hunting them in society before they commit.  This means training all people who may come in contact with them on a regular basis in identifying their behaviors and how to stop them early.  Mental health intervention early and with complete resources and powers is a must.