I really like the shipment idea. Likewise, perhaps add a script that spawns medium class weapons at random locations which are ever changing across the map (of course, only have very few spawn points) - if at all possible. For a criminal, if it just happened to be their lucky day, they might run into one. Or in particularly difficult to access areas, fixed spawn points could be added, in order to help those criminals with slightly lower self-esteem.
The idea about hiding as a criminal would be very effective, for not the spectate mode (like already said

). Just linking to that idea, would it be possible to add a script that completely hides your location, but with movement still enabled, and which you can use as a form of evasion for a fixed amount of time - perhaps a minute, in which time you can make a getaway, and gain a lead on anyone that was after you?
To prevent this lifeline being abused, maybe give the option of only having very few of these options per login/spawn session. Or, another way to do it would be to use random icons which are dotted across the map, which criminals can pick up in order to gain this option. As I know we can't literally create our own icon, this could just be one of those mission checkpoint orbs (such as in the GTA:VC game itself).