After playing GTA Online. Warrants I found were pretty annoying and would kind of ruin game play if you actually wanted to get jobs done. What I could see working however is a heat system. Where if you gain enough attention for attacking any faction (Police, Russian, Colombian, Other) Than they might pay a bit more attention to you if you continue.

For example

Rank One: After 1 or 2 faction attacks. The faction will now draw their weapon on sight if they feel cation around you.

Rank Two: After 5 or 6 faction attacks the faction will attack on site

Rank Three: After 7 or 8 faction attacks the faction would now send men to attack you once a week.

Rank Four: After 10 faction attacks the faction would now send men to attack once a day.

Rank Five: The gang will now stop by your safe house to either attack or harm you.

Now this could get annoying after a while, so the player would have options such as moving to a new location. Not attacking the faction, or giving themselves a new identity, and this could be avoided by using masks/different clothing.

IDK how this would be in practice as I have no game design experience.