Officer Logan was a CIA field operative.
Logan and three other mercenaries were sent to a power plant owned by Hensel Corporation to find important files on the computers as well as switch the stolen vaccine with a faux copy supplied by Sydney. After meeting up with the team and giving them the vaccine, Logan said he and his team needed ten minutes before departure and asked her to make sure the detonator was disabled. She said they were and they had all the time they needed.
Just as they began to sift through the records, Dixon told Sydney that he brought a spare detonator in case the first one malfunctioned. With no other option, Sydney was forced to watch Dixon blow up the building with ther agents still inside, including Logan.
Both Vaughn and Sydney were distraught over Logan and his team's deaths and Vaughn himself went to Logan's funeral, telling his son that his father was a hero.