“Seinfeld” star Jason Alexander writes on Twitter that he received a lot of pushback after he said that he did not “understand people who support public ownership of assault style weapons like the AR-15 used in the Colorado massacre.”

So on Sunday, he posted a long essay explaining his position, reiterating his support of an assault weapons ban but also challenging notions put forward by gun rights advocates on whether the shootings could have been prevented.

Alexander writes, “Then there are the folks who write that if everyone in Colorado had a weapon, this maniac would have been stopped. Perhaps. But I do believe that the element of surprise, tear gas and head to toe kevlar protection might have given him a distinct edge. Not only that, but a crowd of people firing away in a chaotic arena without training or planning – I tend to think that scenario could produce even more victims.

“Lastly, there are these well-intended realists that say that people like this evil animal would get these weapons even if we regulated them. And they may be right. But he wouldn’t have strolled down the road to Kmart and picked them up. Regulated, he would have had to go to illegal sources – sources that could possibly be traced, watched, overseen. Or he would have to go deeper online and those transactions could be monitored. “Hm, some guy in Aurora is buying guns, tons of ammo and kevlar – plus bomb-making ingredients and tear gas. Maybe we should check that out.””

His full essay is here.

On the other side of the spectrum, Rupert Murdoch sent out a tweet on Saturday supporting more stringent gun control laws.

“We have to do something about gun controls. Police license okay for hunting rifle or pistol for anyone without crim or pscho record. No more”