Adrenaline/rush/pucker factor/juice is the result of uncertainty.
Risk is to be held to an absolute minimum during any good op. Most cops are too impulsive and need to wait for back up. Most criminals need to do more preparation and more work on their exits.
Cops and cons are brothers, mirror images. If policework was not dangerous, most cops today would not join up. If the criminal could not stick it to the man, most would never become criminals.
A rookie cop first gets the juice during traffic stops. Then he needs felony stops to get the same hit. Then domestics. Then manhunts or car chases.
A rookie criminal gets a rush at first from shoplifting. Then burglary, because he can’t make enough shoplifting. Then robbery. Then assault and armed robbery. A few make it up to homicide.
There are some people born with an innate love of risk. I urge them to take the time to control it. This can take many years.