My classmates and I frequently said “crim” instead of “criminology” or “criminal justice” when we were grad students in the “Criminology & Criminal Justice Policy” program. It’s too useful not to continue with in some contexts. (I doubt that shortening these disciplines and similar programs to “crim” was unique to us.)
I’ve added an asterisk as a wildcard character here and other places so that it doesn’t look like I’ve mispelled “crime.”