Aleksander Petrovich was one of Milos Kradic's henchmen.
Aleksander was sent to an Indonesian embassy by his employer Milos Kradic, where he warned him not to fail his mission. He entered the embassy and carefully got through the main gates, reaching the center of the embassy. Aleksander put the bomb down and stared at a young woman for a long time, before running out of the building. Seconds later, the bomb exploded, killing 15 people.
Aleksander and his boss Milos Kradic were later seen walking inside a club in Amsterdam in order to meet with a hacker named Linus Halsey, along with Thomas Raimes, who was an undercover CIA agent. Raimes disappeared from the meeting for a brief moment and Aleksander was sent to go check up on him, where he found him walking out of the bathroom.
After Milos agreed to travel to Vienna to acquire Hydrosek, a deadly weapon, Aleksander received information from a third party that Dixon was still working for the CIA (back in the club, Dixon switched places with Halsey and impersonated him). Aleksander whispered the secret to Kradic and just as he was about to kill Dixon, Raimes took the blame and was shot by Dixon in the chest to keep his cover. Kradic, Dixon and his team traveled to Vienna via plane in order to meet the sellers (A Clean Conscience).
When they got there, the deal was spoiled by a mysterious man and the hydrosek sellers were killed. CIA agents began to engage in a firefight with Kradic and his men and Aleksander held Vaughn at gunpoint. Dixon quickly took out his pistol and shot Aleksander in the chest (Mirage).