voting and citizenship

It seems to be a matter of common sense that a person who wishes to vote must prove his citizenship.

Not only is this not required, it is illegal to require proof.

wikipedia explains that:

The National Voter Registration Act requires States to "accept and use" a uniform federal form to register voters for federal elections. 42 U. S. C. §1973gg–4(a)(1). That "Federal Form," developed by the federal Election Assistance Commission (EAC), requires only that an applicant affirm, under penalty of perjury, that he is a citizen.

Arizona law, however, requires voter-registration officials to "reject" any application for registration, including a Federal Form, that is not accompanied by documentary evidence of citizenship. Respondents, a group of individual Arizona residents and a group of nonprofit organizations, sought to enjoin that Arizona law.

Ultimately, the District Court granted Arizona summary judgment on respondents' claim that the NVRA preempts Arizona’s requirement.

The Ninth Circuit reversed, holding that the state's documentary-proof-of-citizenship requirement is preempted by the NVRA.

On June 17, 2013, the U.S. Supreme Court ruled against Arizona in the case Arizona v. Inter Tribal Council of Ariz., Inc.. The Court held the NVRA preempted a 2004 Arizona proposition, Proposition 200. It was a ballot initiative designed in part "to combat voter fraud by requiring voters to present proof of citizenship when they register to vote and to present identification when they vote on election day." Purcell v. Gonzalez, 549 U. S. 1, 2 (2006) (per curiam). It was a 7-2 decision striking down the law.

Justice Antonin Scalia wrote the majority opinion.

https://en.wikipedia.org/wiki/National_Voter_Registration_Act_of_1993

Modern active shooter protocols

The FBI says:
https://www.fbi.gov/about-us/office-of-partner-engagement/active-shooter-incidents/active-shooter-planning-and-response-in-a-healthcare-setting

Prior to Columbine, an active shooter incident would have been considered an operation to be handled by a SWAT or tactical unit. 

Lessons learned from this tragedy included the need for all police officers to be properly trained, equipped and empowered to immediately intervene in an active shooter situation to stop the ongoing violence regardless of their assignment.

Modern day law enforcement training and tactics dictate that the primary objective of the first law enforcement officer(s) on the scene of an active shooter situation is to locate and stop the person or persons believed to be the shooter(s). As law enforcement active shooter training has evolved, there has been a move away from waiting for several officers to arrive and form a “team” prior to searching for the shooter. 

 Today, many agencies and trainers recommend a solo officer entry into an active shooter situation if it is believed the officer on scene can locate, isolate and/or stop the shooter prior to other arriving law enforcement officers. The solo officer entry can be a very dangerous response strategy. However, properly trained and equipped police officers acting alone without the benefit of backup have stopped ongoing active shooter situations, thereby saving lives.

This type of rapid response was implemented in this incident.

https://en.wikipedia.org/wiki/Shooting_of_John_Crawford_III