The man who killed 12 people at the Washington Navy Yard on Monday "had a record of misconduct," according to a Navy officer, and apparently struggled with mental health issues.

So some readers are asking: How did Aaron Alexis get a gun?

So far, the letters sent to us betray a kind of war-weariness among our readers over mass shootings. They also express exasperation with the failure of our politicians to act on gun control even in the wake of tragedies such as the massacre in Newtown, Conn., last year that took the lives of 20 elementary school children. Some even say the are no longer surprised to hear of such mass shootings.

PHOTOS: At the scene of Navy Yard shooting

As I've written before, the preponderance of letters we receive on gun control tend to favor more restrictive laws, and most of the reactions here reflect that. In addition, some readers cite other cultural factors in the U.S. that may lead to mass shootings, and a scant few say this massacre is an argument against increased gun control.

Here are some of those reactions.

Los Angeles resident Ron Landesman laments the easy access to guns in America:

"Just another day of freedom in America -- freedom for law-abiding citizens to obtain and own dangerous guns.

FULL COVERAGE: Navy Yard shooting

"That this privilege inevitably allows these weapons to easily end up in the hands of dangerous people does not seem to matter. It is apparently more important for gun enthusiasts to have the right to play with whatever toys they choose than to take action to prevent another massacre.

"This is a freedom that makes me ashamed to be an American."

Oren M. Spiegler of Upper Saint Clair, Pa., says it will only get worse: 

"A radio station that I listened to on the day of the latest gun massacre described it is 'a surprise.' The president asserted that the victims encountered 'unimaginable violence that they wouldn't have expected here at home.' 

"Both accounts are wrong.

"Ours is a country that is rife with mental illness, rage, hatred and the easy availability of guns that are designed to mow down human beings in rapid succession. We have seen this pattern time and again, so what is 'surprising' or 'unimaginable' about it?

"Additionally, mass murderers know that their actions will be a ticket to have their life story and photo topping every television newscast and to appear in every newspaper. What could be more tempting for the sick mind that equates infamy with fame?

"An end to instances of mass gun murders is not on the horizon. We are going to be living in an armed camp as the number of places in which we can expect to be safe becomes smaller."

Loren Lieb of Northridge shames the gun lobby:

"For decades we have allowed the gun lobby to set our national gun policy. It has been a perilous experiment that has cost American lives.

"The gun lobby's only interest is to sell more guns, plain and simple, so it steadfastly opposes any and all attempts to implement the most common-sense regulations, such as requiring a background check for every firearm purchase. Too many spineless politicians kowtow to the lobby's demands. 

"Mass shootings committed with dangerous weapons easily obtained by dangerous people have become commonplace. It's time to establish a national gun policy that has saving American lives as its priority."

Pasadena resident John W. Hazlet Jr. has a different take on gun control:

"Glad to see that Washington's ultra-restrictive gun laws work as well as other similar laws throughout the U.S."

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