[YeahBuddy]

I just saw this picture you posted after I had previously posted about the “professional assassin.”

Those are unfired cartridges. This jives with the shooter working the slide because he had a malfunction, at least twice. It doesn’t appear to be a Welrod either, the firearm slide skinnier than the silencer which denotes an attachment. I believe the entire barrel of the Welrod is one piece.
Why the need for a silencer when you are going to shoot somebody in front of people in a public place anyways?

The totality of all these circumstances doesn’t add up to a “pro” for me.

Again, this is just my 2 cents.

[NautiNurse]

The totality of all these circumstances doesn’t add up to a “pro” for me.

My first clue was the first shot to the leg. Big miss for a "pro."

[Governor Dinwiddie]

I'm pretty sure any amateur gunsmith could manufacture a welrod starting with a bolt action rifle (as the British did in WWII).

[HIDEK6]

This jives …

Why do I have to be the bad guy?

Jibes.

[Fireone]

“Why the need for a silencer when you are going to shoot somebody in front of people in a public place anyways?”

Perhaps, to limit his audience to 3 or 5 people, instead of 300?

[Bonemaker]

“The totality of all these circumstances doesn’t add up to a “pro” for me.”

2 tells for me:

1. Stance/footplacement..not that of a skilled pistol shooter;

2. Ditto for extended but bent at elbow right arm.

[4yearlurker]

I'm thinking maybe he didn't want to activate the Shot Spotter (if NYC has them installed) where the cops could pick it up after the first shot. It would also give him more time to make his escape.