Very simple change.
If a player becomes a suspect, by any means, then anyone who has safeties turned down to yellow can engage them without warnings, and they receive the limited engagement timer.
If they have green safeties, they will receive the warning that engaging that player will give them the limited engagement timer, and the suspect will be able to fight back without any CONCORD intervention.
Now, for the main change.
If a suspect player does another suspect action before their suspect timer runs out, they will become a criminal, and anyone, even with green safeties, can engage them without receiving an engagement timer.
Same system of getting two yellow cards gives you a red one, and you are out.
This limited engagement mechanic only serves as some cheap bait for new and unsuspecting players, as suspects can simply come back with a properly fitted PvP ship after dying in something silly and inexpensive, like a corvette.
It’s also a prime tool for harassment, with criminals being able to shoot MTUs and loot them without the victim, who knows better not to engage them, being able to defend their possessions.
With this system, shooting an MTU would give the first suspect timer, and looting it afterwards would make the player a criminal, requiring some extra effort of getting a thief buddy to help you out commiting crimes, or the risk of having to GTFO before the victim gets back at you.
Makes no sense for a thief to come rob me, and then follow me around waiting to rob me again without any form of police coming to deal with them, and if I decide to punch them in the face, the police will do nothing even if they stab me in public, because “that’s a limited engagement and stuff”.