Many times when you get a case, you have extremely limited information. But when you get the case like from a briefcase or a guy talking, you atleast have an oppertunity to look into who it is who's hiring you. Then snooping on them could reveal more tangible leads!
You can find fingerprints on briefcases for example, and you're told which division enforcer jobs are from. This would add another cool layer to the investigation i think!
On that when people call you on a payphone, or bar, i think it should be possible to trace the call, so you have a chance to find out who it is hired you.