Witnessing for Enforcers

Press the Alt key while a criminal is committing a crime (they will have a symbol of handcuffs above their head while witnessable.)

Witnessing System
 
To witness a crime: firstly you must be an enforcer, and second you must find a criminal that has committed a crime. A pair of handcuffs will appear next to the right of their name if they have broken the law. Breaking the law can consist of damaging property, shooting at cars or civilians, mugging, or stealing cars.
 
Enforcer Objective after Witness - Once the witness is performed successfully, a mission will begin against the Criminal. Kill the criminal and take back the stolen items from them and turn it into the Evidence Locker before the mission time runs out.
 
Criminal Objective after witnessed – Once the criminal is witnessed by an enforcer, a mission will begin against the enforcer. Criminals should turn the stolen items in the Money Launder before the mission time runs out.
 
If the time runs out before either Enforcer or Criminal turns the stolen item, the person holding he item wins the Money and the Mission.