I agree that she is to blame because she knew that her son was mentally ill therefore she should've taken more caution to the choices in which she made. If she decided to own a gun that is her own decision but she should've known better as to how she would keep the gun away from her son.
Yes Nancy Lanza are to blame on sandy hook shooting.She is irresponsible on her son.It's not about video games or mental ill that are to blame in this case.I believe guns avaibility and parents are to blame on school shooting.Many countries has gun control,and this is far less violent than US.
By letting her known mentally handicapped son handle weapons she is not following proper firearm safety. She should have enough knowledge to lock up the guns she has in her house in a proper safe to which only she knows the passcode. She is irresponsible to the point where I would not trust to leave her with firearms lest she arm her cats for world domination.
When you create a society in which everyone has free and easy access to a killing machine, it is no surprise that there a few within that society who use it against the society. If you want someone blame, America needs to look at themselves. Gun control should have been brought in after the first massacre and their refusal to do so means that every death after, as a result of a lack of gun control, is their fault.
She is not to blame. Each person is responsible for his/her own actions. She can not stop her son from committing atrocious actions. Where does the chain stop, if we say she was to blame for leaving her guns within her son's access? Was it the gun seller's fault for not doing a complete and thorough background check on her family situation? Was it the gunmaker's fault for not providing clear guidance on this sort of thing to the gunseller? As for the person who invented the gun, is it his fault that people use guns to kill? No. Definitely not. People make their own decisions. She should not have let her son have such easy access to guns, but the ultimate result of HIS actions is not her fault.