ABC News has posted video of the shooting that occurred on June 29, 2016. A single male approached the White House on foot, openly carrying a gun in his hand!
What in the world did that idiot think was going to happen? That he’d be invited inside for tea? As it is, I think the Secret Service treated him with the greatest of gentleness. They only shot him once, after all.
The gun appears to be a Ruger Mk IV, the target model.

This is a handgun chambered for the .22 Long Rifle cartridge. It is a rugged and extremely durable gun, and it is very useful for anything you might want to do with a handgun chambered in .22 LR.
By the phrase “… anything you might want to do with a handgun chambered in .22 LR…” I mean hunting small game or target shooting at the range. I don’t think it is appropriate for walking up to the White House while openly displaying a gun. But, then again, I don’t think any gun on the planet is appropriate for that!
I used an earlier version of the gun during my charity self defense course. It was a Mk II, and was similar in many respects to the Mk IV.

It was an essential training tool, and thousands of people were introduced to the shooting sports via this gun.
Of course, the guy who got shot outside the White House used his to get introduced to prison and life after a potential felony conviction. I don’t recommend using them for this purpose.
UPDATE – Robert Evans very kindly points out that the date stamp on the video was 4 years ago, and he has my thanks. I have updated the essay to indicate the correct date.