He was first assigned to kill Jason Bourne, along with Castel and The Professor. He never reaches Bourne, but was later reassigned to kill Alexander Conklin by orders of Ward Abbott. Manheim later waited in a red Renault Twingo hatchback and is seen attaching a suppressor to his Beretta M9. As he steps out, he confronts an injured Conklin and subsequently shoots him twice in the chest and then delivers a final headshot to finish him at close range. He then contacts Treadstone to inform them that his last orders had been carried out.
It is possible that he died of natural causes shortly after since Jarda tells Bourne that he and Bourne are the only Treadstone assassins left.
In the game, he is followed by Bourne into a nearby church. The two have a shootout inside the church, whereby Manheim blows up a gas tank, causing the church to catch fire. After a lengthy fist fight outside, Bourne delivers a lethal blow to Manheim with a shovel, sending him plummeting to his death.