Man in Leather Jacket was an SD-6 hitman.
The man in leather jacket and Jonathan Potash were on a stakeout while Vaughn and Sydney were having dinner inside a restaurant. After scanning Vaughn's face through the DMV database, the man and his partner found out Vaughn worked for the CIA.
The duo ambushed the couple's dinner and tried to kill them both; they fled the restaurant through the back door and into an alleyway. While escaping from the man in leather jacket, Jonathan showed up in a car at the other end of the alley and forced them to hold up their hands and get on the ground. As Jonathan called Ariana Kane to inform her that they captured Vaughn and Sydney, the other man began to tie them up. Before he could tie up Vaughn, he stabbed the man in the throat with a concealed knife and took his machine gun. Jonathan was quickly gunned down afterwards.