Those who are pro gun control, see the Ottawa Parliament shooting as just another reason to promote gun control here in the United States. On the other hand, the anti gun control side points to the fact that, if the Sargent of Arms hadn't had a gun in his possession and used it, there could have been many more that were killed. They also believe that, even if the gunman had no access to a gun, the religious fervor of the Ottawa terrorist would have driven him to use some other type of weapon; a bomb or even a hatchet; as was seen just recently in New York.
The simple fact is that, unless two-thirds of Americans turn in favor of gun control, it isn't going to happen because it will take that large of a majority to amend the Constitution's specified right to bear arms. Further, there are millions of guns out there with nearly every bad guy owning at least one. If there is gun control, only the law abiding would be left without protection against the evil that resides in this country. The criminals will always be able to get guns and rifles through smuggling, or through the black market.