Merely riding in a stolen car, without more, cannot result in a criminal conviction. However, a person who rides in a stolen car knowing that the car has been stolen (or under circumstances where the passenger should have known that the car was stolen) could be convicted of a crime, as can any person who aids or assists in stealing a car or driving a stolen car.
A person commits the crime of auto theft or larceny by taking or exerting control over a vehicle that belongs to someone else without permission and with the intent to deprive the owner of the vehicle. In some states, possession of property that the defendant knows has been stolen is also a type of theft. In other states, receiving stolen property is a separate offense. For example, a person who buys a car, knowing that the car has been stolen, could be convicted of a crime. For both theft and receiving stolen property convictions, there must be some evidence that the defendant exerted control over the property, even if someone else also exerted control over the property.
A passenger in a stolen car could be convicted of theft if there is evidence that the passenger exercised some control over the car and knew that it was stolen. For example, a passenger who directs his girlfriend to steal a car and drive the stolen car to a friend's house could possibly be convicted of theft.
A person commits joyriding by driving or using another person's vehicle without permission. Some states refer to joyriding in criminal statutes as "unauthorized use of a vehicle." Joyriding tends to be a less serious offense than theft because the intent behind the offenses is different. To prove theft, the prosecutor must show the defendant intended to "permanently" deprive the owner of the car. For a joyriding conviction, the requisite intent is usually a "temporary" deprivation.
Some joyriding statutes are broad enough to include not only the driver of the car but also any person who is in the car without permission from the owner. In order to be convicted, the joyriding passenger must have known that he or she does not have the owner's permission to be in the vehicle. For example, suppose a friend picks up the defendant in a truck the defendant knows the friend has taken without permission. The two then use the truck to commit a robbery and split the money before returning the truck. Both friends could possibly be convicted of joyriding (along with other crimes).
Usually, a passenger cannot be convicted of any crime unless he or she knew or should have known that the vehicle was stolen or used without the owner's permission. For example, a hitchhiker who was picked up in a stolen car could not be convicted of an offense if there is no evidence that the hitchhiker had any reason to believe the vehicle was stolen. By contrast, if two friends are picked up in a stolen car, and the passenger knew that the driver did not own a car, the passenger might be convicted of a crime.
States vary in their penalties for auto theft and joyriding offenses. Often, joyriding offenses will carry less severe penalties than theft, but penalties might increase depending on the circumstances (such as taking the car to commit another offense). Joyriding could be a misdemeanor or felony-level offense. In most states, auto theft will be a felony. Penalties for auto theft may increase as the value of the car increases.
For the passenger riding in the stolen or joyride vehicle, the severity of the penalty often depends on the degree of the passenger's involvement in the crime. The mastermind behind a car theft will often be sentenced to a longer sentence than a friend who just goes along for the ride. But that's not true in all states. Some states penalize the knowing passenger the same as the driver.
A conviction for theft or joyriding can have serious consequences, including time in prison or jail, a fine, and a criminal record. If you are charged with any crime, you should talk to a local criminal defense attorney. An attorney can tell you what to expect in court and help you successfully navigate the criminal justice system.