He was able buy two guns a couple weeks prior.
The FBI wasn't told of the purchases.
The purchases couldn't be blocked because he had ever been on the watchlist.
You can't get on an airplane with a full bottle of shampoo but you can buy an AR-15 even if you are on the terrorist watchlist.
The 9/11 terrorists used airplanes as weapons and so access to airplanes is restricted.
This attack against a Latino gay community is more about religious homophobia than Islamic terrorism. The religious right does not care about any of these people.
I want every gun registered.
I want every gun owner trained, licensed and registered.
I want every gun transaction recorded.
If that means the second amendment needs to be amended, so be it.