Payday 2: 10 Crucial Tips & Tricks The Game Doesn't Tell You
6. Custody, Hostages & Domination
Hostages are not only a source of health - if you take certain skills from the mastermind tree - but also necessary if one of your team mates gets downed too many times and ends up in custody. Shouting and cuffing any civilians or guards should be a priority at the start of maps if you want to have a plan B. Plenty players also don’t realise that having hostages delays police assault waves by precious seconds.
Similarly hitting that "F" key until a regular boy in blue submits and kneels allows you to convert them to your side giving them a friendly blue outline and following you as your very own human meat shield. Note - friendly fire works on converted cops. For the love of various gods DO NOT shoot your teammates newly-converted friends. You will make everyone hate you.
Lastly, in a pinch, already-converted cops can be exchanged for a teammate in custody if no other hostages are available.