Answer:
gerund
Step-by-step explanation:
The thief confessed to stealing the camera from the display. The italiced word is a gerund because it functions as a noun. Stealing is the object to the preppsition to and a preposition is always followed by a gerung . If the thief confessed to stealing the camera, in fact, this is what is meant: The thief confessed to someone that he had stolen the camera. The italiced clause can be nominalised through a gerund preceded by a preposition as the one in the original sentence.