Final answer:
The question relates to a subplot in Steinbeck's Of Mice and Men where Carlson suspects Lennie has stolen his Luger pistol, but the provided text is from Zane Grey's Riders of the Purple Sage, which does not contain these characters or elements.
Step-by-step explanation:
The question "Who does Carlson think has stolen his Luger pistol?" refers to a subplot in John Steinbeck's novel Of Mice and Men rather than the excerpt provided. Unfortunately, the passages offered are from a different novel, Riders of the Purple Sage by Zane Grey, which does not contain the character Carlson or a Luger pistol.
In Of Mice and Men, Carlson is a character who owns a Luger pistol. The correct answer, respective to Of Mice and Men, is that Carlson suspects that Lennie has stolen his Luger pistol after it goes missing following the death of Curley's wife, which Lennie was responsible for.