Herman Geier

Herman Geiger was a Abstergo doctor, who in 2012 went undercover in the Assassin Lucy Stillman's team.

While travelling in a van, the Assassins were attacked by Templars. After they fended off the attack, Geiger suggested that Abstergo planted a bug on Lucy Stillman or Desmond Miles, saying that was the reason they were found. However, the Assassins couldn't find a bug, and they resumed their journey.

After Desmond went to relive more of his ancestor Aquilus' memories in the Animus in the van, he discovered the meaning behind the phrase "The eagles don't fear the vultures, but they have to start being cautious." While they were having a discussion, Desmond asked for Lucy's gun, and shot Geiger in his leg. After showing a phone he took from one of their Templar attackers and pointing out that a phonecall was made to Geiger, he finished Geiger with a bullet to the head.

Source

 * Assassin's Creed - French Graphic Novel: Tome 2, Aquilus