The key is put the lies out early before people start thinking about what you are saying. Lets look at your topic paragraph.

“Guns and the workplace haven’t proved to be good partners. Between 1980 and 2006, there were 16,459 homicides by shooting in the workplace. ”
How many of these shooting were legal? or in accordance with company policy?

“Various state laws made it possible for employers to do this, serving as a welcomed barrier between guns and the workplace.”
What laws are you referring to? I am not aware of any laws that restricted companies ablity to create company policy about weapons on campus.

I suggest a new sentence for you.
“Criminals and the regulations haven’t proved to be good partners. Between 1980 and 2006, there were 16,459 homicides by shooting in the workplace.”