There is a common misconception that everytime someone is arrested they must be read their Miranda rights. The fact is that Miranda rights need only be given if a person is taken into custody and then questioned.  If they are questioned before an arrest, they  need not be read theirr rights. It is only if there are questioned after being arrested, that the arrest may be unlawful. In other words, if you are arrested and then asked questions about the alleged crime, a Miranda warning must be given.  If it is not, then anything that you say after that point may not later be used against you.  Based on the limited facts presented, it's not clear if you were questioned before or after an arrest.  At this point, if needed, you should consult directly with a criminal defense attorney in your area.