Why gun control always fails..
I've even heard people call for some to be denied their civil right to defense if they have a family member that is mentally unstable. Denying access to what even the Supreme Court has said is a fundamental right because of who somebody is related to, is obviously unconstitutional. In the case of Newtown killer's mother, we don't even know how she secured the firearms which the killer took but the truth is that killer could have simply held a steak knife or knitting needle to her throat and force her to give him access before he killed her.... we don't know what happen yet but with a little thought you start to see how ridiculous it is trying to prevent this sort of crime with registrations and laws that would deny people human rights based on their relatives.
Magazine limits, gun bans and registration (what expanded backgrounds checks really mean) not only wouldn't stop some murder, they wouldn't stop any murders at all. Because they can't. (They would however negatively effect law abiding citizens ability to defend themselves.) The reasons for this is the same reasons all gun control always fails. It's literally not possible to achieve the stated goals of reducing crime through gun control for very basic reasons. And just looking around at even very recent history we know that registration as never been able to reduce crime. Canada eliminated their long gun registration recently after many years because it was totally ineffective for reducing crime. It did however, lead to confiscations for law abiding citizens, as registration always always does.
Here's some facts to consider:
Hollywood movies and biased news media not withstanding, firearms are only one of an INFINITE number of tools with which criminals may commit murder and/or violent crime. I don't mean that only in the abstract but it is especially so because of the specific dynamic between an attacker/s and defender/s. Because of this specific dynamic (which I'll explain further,in later paragraphs), practically anything can be, has been, will be and is used to murder and often with far greater efficiency than firearms. So even if it were possible to eliminate firearms from the equation all together (of course it is not) it still would have absolutely positively no demonstrable effect on reducing the rate of murder or crime. None. There is however significant evidence actually showing the opposite effect.
Firearms are popular with criminals for various reasons but actually are not the most effective tool for murder. This should be obvious but incase you're not sure, 85% of people shot do not die (95% if you get medical attention immediately). If somebody really wants to murder somebody or a group of somebodies there are many many more effective ways of accomplishing that goal than trying to make small inexact holes in them with firearms.
Firearms as a tool are convenient/portable and allow one to engage at more distance then many other tools. However, this one advantage "convenience" is never high on the priority list of criminals/crazy bad guys because they always have the inherent advantage of getting to pick the time, place and manner with which they will attack. That more than anything is why there are always an infinite number of tools available to an attacker. If one tool doesn't fit their needs they simply change the tool/s or number of tools. Or they change some combination of variables (time, place, manner, etc) to achieve their goal. If they can't get a particular tool legally, they can simply obtain it illegally or change the tool/time/place/manner/etc. This goes for common criminals and serial killers. Specific tools do not actually cause violent crime as there are an infinite number to chose from. The decision to commit murder is never depended on any one tool. This even includes suicide. People make a conscious choice to murder just like they make a conscious choice to commit suicide. These decisions are never based of the availability of one particular tool. Which is why places like Japan (no guns) can have twice the suicide rate of places like the US. Additionally, every study shows mass killers ALWAYS meticulously plan out their crime. Often for many years and will go to unbelievable lengths to achieve their fantasy/goal.
This is evidenced by (among mountains of other things);
The worst foreign terrorist attack and mass killing in US history, no guns were used at all. (9/11)
The worst domestic terrorist attack mass killing in US history, no guns used what so ever. (OK City)
The worst school mass killing in US history no guns were used. (Bathe MI) Even though it happened in a time when not only were there no backgrounds checks for any firearms what so ever but anyone could buy and own fully automatic firearms with no special procedures at all.
Most famous murder trial in US history (OJ Simpson) no gun used. (Although I bet the victims wished they had been armed)
Murder (mass and otherwise) has existed for ions prior to firearms and it exists even where there are no firearms what so ever. (Ask people in prisons how safe they feel)
For the entire history of firearms even with ALL the places in the world that have strict gun control and/or outright bans, gun control measures have never been shown to reduce violent crime/murder.
Conversely, there is practically NO tool that is more effective for defense then a firearm. That is because of the specific benefit offered by firearms (convenience/ability to engage at distance) IS especially critical for a defender. By definition a defender does NOT get to pick the time, place or manner with which they will need to defend themselves. They are always at this inherent disadvantage. So (unlike an attacker/bad guy) the convenience offered by firearms IS paramount to a defender/good guy. It logically follows that restricting access to the best/most convenient tools for defense /firearms (and by extension the convenience of normal-extra capacity magazines) can only possibly have a negative effect on the ability to defend (the good guy). Since again convenience is ONLY paramount to a defender then practically speaking, degrading convenience will NEVER have ANY effect on an attackers ability to attack.
These reasons are why gun control has never been shown to reduce crime anywhere, ever. With the logic and supporting facts, examples and history listed above the reasons should be more than somewhat apparent why, but even if not, then you have to ask yourself shouldn't there be at least a few examples of it's success? And if there is not, given the enormous number of attempts throughout the world and history, isn't the lack of success evidence in itself? In essence this total lack of success actually only supports the other examples, numerous studies, history and core logic of how gun control simply can not possibly achieve its typically stated goals (reducing crime).
If you leave emotion out and logically think through and look at the mountains of empirical data and long world history, it becomes obvious that expanding background checks (in effect registration which we know ALWAYS leads to confiscation) magazine restrictions, gun restrictions and bans, actually all gun control, have absolutely NO effect what so ever on reducing murder (mass or otherwise). It can't. It's simply not possible for gun control measures to have that effect. Regardless of how counterintuitive it may be to those who's perception of reality are shaped by the main stream media and/or entertainment industries. We really don't have to guess as we can just look around and see that. On the other hand we know registration, and further restrictions would severely infringe on a basic human right and have a significant negative impact on the natural right of defense including the ability to resist tyranny.