Stealth is used to determine how visible your scents are when you commit a crime. The criminal's Intelligence*Stealth is weighed against the tracker's Perception*Exploration. The tracker will only be able to see the criminal's scents if he has at least half the criminal's Int*stealth, and will only see them half the time if they are equal, similar to seeing forgeables. The criminal's Int*stealth will also affect the tracker's pie slices when tracking them, from a very precise direction to a very broad one, and affects the cool down of a scent when used. The higher the criminal's int*stealth is compared to the trackers per*exp, the longer it will take to cool down.
Note: Your own scents do not care that they came from you. So, depending or you attribute levels, you might not see your own scents.