We would like you to assess the QUALITY of each of the following argument (discussing Gun Control) and determine if the argument is Valid or Invalid. A valid argument is clearly interpretable and either expresses an argument, or a premise or a conclusion that can be used in an argument for the topic of gun control. An invalid argument is a phrase that cannot be interpreted as an argument or not on the topic of gun control.

That would theoretically work except the fact that more knife murders may occur then and perhaps guns will be brought in illegally to murder people.
Valid

Under English common law, the Castle Doctrine was intended to be a narrow exception to the general duty to retreat.
Invalid

Using illogic, skewed statistics, revisionist history all in an attempt to violate my constitutional rights, that would be you and other gun grabbers who are trying to infringe on law abiding citizens rights.

Valid