casing the joint

Verb

case the joint (third-person singular simple present cases the joint, present participle casing the joint, simple past and past participle cased the joint)

1. (idiomatic, slang) To thoroughly observe or examine a place, in order to familiarize oneself with its workings in preparation for criminal activity, often robbery.
2. (idiomatic, slang) To thoroughly observe or examine a place, without any nefarious motive or intent.