Answer:
The answer is: Larceny....furtive
Explanation:
Larceny is a synonym for theft; larceny is more formal. And furtive means shifty, clandestine or ilegal. So as you can see, from context you can infer that it's these two words, for the "commit", "thief", "sneaked into", and "manner", you infer in this last one that an adjective it is. And well, a matter of collocations, you can commit: suicid, a crime, a mistake, a sin, among others; but you can't commit camaraderie (team spirit?) sounds strange, you can't also commit longevity (long life), neither the last one (false moralty).
