If you are caught with three marijuana roaches and the cop lets you because you told him you would call him with information about your dealer, if you don't call back, what could happen?

Possession of under 30 grams of marijuana is a class A misdemeanor in Indiana. In some other states it is a petty offense punishable only by fine. The time limit for bringing charges depends on the statute of limitations for drug offenses in your state. It is usually a period of years. Thus, if you don't call the police officer and provide him the information he is expecting from you, he may ask the district attorney to file a misdemeanor charge against you. However, you possessed a very small amount of marijuana. Indiana also allows for "conditional discharge" of persons convicted of possession of marijuana for the first time. This would allow you to plead guilty but the court would then defer further proceedings and place you under supervision for a period of time. If you don't violate the terms of your supervision, at the end of the term, the court will dismiss the charges against you and you will not have a record of conviction for the misdemeanor. You are under no obligation to provide information about others to the police. You may want to retain the services of a criminal defense attorney who can call the police officer and relay your decision not to incriminate others and arrange for you to receive a summons for the marijuana charge so you won't have to be arrested or post bond. It is generally not advisable for potential defendants to directly contact the police because anything you say can, and likely will, be used against you.