|Behind the scenes|
Hit in the face by John McClane, either killed by this or survived and was arrested afterwards.
- ""But Karl's up there!""
- ―Kristoff to Hans
Kristoff arrived in the Pacific Courier truck and was helping Heinrich load the equipment to the vault on the 30th floor of the Nakatomi building. He assisted Theo with the locks on the vault. When the vault was finally open, Kristoff expressed his joy about it and helped Theo, Hans and Eddie gather the bonds, with hostage Holly McClane in tow. Upon learning that the hostages are coming down from the roof, and that John McClane had alerted them of their plans, Hans orders Kristoff to blow the roof. Kristoff protested against it, as Karl was still up there, along with Uli. Hans then took the detonator anyway and set off the explosives. When the roof exploded, it destroyed Special Agent Johnson and Agent Johnson's FBI helicopter, and John McClane narrowly survived by tying a fire hose to his waist and jumping off of the skyscraper. As Hans and Eddie finished emptying the vault and John McClane used his Beretta 92 to shoot through a window and gain access back into the building, Kristoff began running towards the parking garage with a bag of negotiable bearer bonds to meet up with Theo, who was unloading the getaway ambulance from the Courier truck. However, as Kristoff was running through the hallway, John McClane leaped out at Kristoff, striking him in the face with the butt of the MP5, sending him head first onto the floor. Kristoff's fate is never confirmed, and it can be assumed that Kristoff was killed when McClane struck him (possibly from a fractured skull), or he could have also survived and was arrested along with Theo and sent to prison.
- Kristoff has only a couple lines in the entire movie, most of which are in French and very short. He only has a minute or two of screen time in the entire movie because he is on the 30th floor for most of the film where he is helping Theo. Because of these factors, Kristoff is often forgotten about completely by many fans of the film and even some of the characters in the film, who often state that there are only twelve terrorists (posters included), when Kristoff is in fact, the thirteenth.
- Clarence Gilyard Jr., the actor who played Theo, claimed he was the only terrorist to live, implying Kristoff was most likely killed by John when he attacked Kristoff inside the vault.
- "But Karl's up there!" (In-movie quote)
- "But Karl and Uli are up there --" (Scripted but unspoken)
- "Damn! It didn't go!" (Scripted but unspoken)
- (deleted scene) "Je ne veux pas mourir dans cet endroit!" (I don't want to die in this place!)