

3) Despite what some people have said, "David" never admits or indicates that his face was altered. 2) When "David" is attacked by Major Carver and his team, he admits to Laura that he really did know her son and that they were in the same program, another proof that they are two different people. This theory is not true, and the reasons are: 1) In one of the first scenes, "David" and Caleb are shown on a picture together, which proves that they are not the same person.

Some fans have suggested that "David" is actually Caleb. This promise was strenghtened by the supersoldier program. It is also probable, that they were close friends and "David" made a promise to take care of Caleb's family in any way possible, if something was going to happen to Caleb. Based on a photo of Caleb and his comrades, it's reasonable to assume that "David" really knew Caleb, who was probably killed in the Middle East, while "David" was injured and sent back to the US. No one could have predicted, that "David" would be so dangerous - that is why he was able to escape so easily. Ironically, he was originally chosen for the experiment, because of his strong empathy levels. He burned their bodies to cover his tracks and assumed the identity of "David", who was also a part of the 'Project Aegolius'. Later, while KPG had him under study, "David" killed several people and escaped. Not just fear, but also empathy and guilt. In the process, he'd lost his ability to feel.

He volunteered for a procedure that would turn off his pain receptors and allow him to consciously regulate the flow of adrenaline in his body. Major Carver reveals to Anna that "David's" spine was injured in combat, and even after surgery, he was still in pain. While the footage elaborating on "David's" backstory was deleted after test screenings, the original script gives more insight on what he is. Even Wingard and screenwriter Simon Barrett admitted that they hated explaining David's character and his background because they always wanted to leave much of the information about him ambiguous, which is why they were glad that those scenes were disliked by the test screening audience and had to be cut out of the film. These scenes were cut because the test audience felt that all of it was just too much information. Some of the scenes which were cut down or deleted completely after test screenings were scenes which explained what exactly "David" is, what happened to him, why he does some of the things he does in the film, and more details and information about the KPG program that he was involved in. After another test screening, the audience was confused at the sudden arrival of Major Richard Carver and his team at the Peterson home, which is why some scenes with Carver at KPG headquarters were added in final cut of the film. After this version was screened to a test audience, it was cut down to the running time very close to the run time of the theatrical cut. According to director Adam Wingard, the original rough cut of The Guest was over twenty minutes longer than the final theatrical cut.
