In Scandal season 6, episode 6 - Extinction, we see that
Ely is directly responsible for shooting Frankie Vargas.
But I don't understand why he did it himself. He had a patsy all set up across the street who allowed himself to be caught and fall under suspicion anyway. The patsy had to fire some shots anyway so why not just shoot the target? I'm sure it wasn't because there was a chance of him missing as he was a highly trained agent.
Furthermore, it opens up some plot holes in that the ballistics and angle of impact won't match a sniper rifle being fired from across the street.
Also, it seems odd that both a police officer and secret service agent were killed/incapacitated by the tunnel entrance and this did not arouse suspicion that perhaps all is not what it seems.