EDIT 4 Information in title is misleading and has been clarified below.

I was listening to the Major Nelson podcast earlier this week where he interviewed Steve Papoutsis of Visceral Games to talk about everything Hardline leading up to the release. They were talking about the reasons for weapons licensing and I very distinctly remember Steve saying that once a license is purchased, the gun can then be used with any class (professional, mechanic, etc) as well as with either faction (cops, robbers).

This was the first time that I have heard anything about being able to use the weapons between each class and checked the wiki for more information. The wiki states that a license allows you to use weapons between faction and NOT class. I may be getting my wording mixed up, but was hoping someone could correct me if I am getting this wrong.

PS. really looking forward to this game!

EDIT OK! Just listened again. His example definitely states that you can bring guns with you between classes once they are unlocked.

Here is the link Go to the the 54 min mark on the podcast to hear him explain this.

EDIT 2 Thanks to user /u/Zergonaplate here is a direct link to the discussion in the podcast which starts at the most important part:

YouTube Link

Edit 3 The Hardline team has spoken. License only applies to factions and will not be shared between classes. Sorry if this created any confusion for anyone but I am glad that it got cleared up now. Thanks Visceral guys that chimed in to help with the discussion.