Crimes require nerve, how much varies on what crime, and what part of the subcrime you are committing at that moment. A successfully committed crime gives you Crime Experience (CE) and Crime Skill (CS). Crime Experience is a hidden metric, it helps determine the Natural Nerve Bar (NNB) and influences the success rates in Organized Crimes (OCs, this is a crime that is scheduled by your faction). CE is not tied to any particular crime or OC, and there is no cap on the NNB, although as you increase, each increment of 5 is harder to get. Crime Skill is a metric measured in levels for each crime, which is displayed in the level bar you see over each crime. Each Crime has Sub-Crimes, some are locked until you level up in that specific crime, some are available at level one. You may also need to find/buy a special item to unlock some sub-crimes. The crimes list so far is as follows: Search For Cash Bootlegging Graffiti Shoplifting Pickpocketting Card Skimming Burglary Hustlin...
Just what I've gathered playing and reading.