Miranda speaks to custodial and interrogation. If you where in custody when you were interrogated, Miranda (and progeny) requires the police to inform you of your rights. The penalty for failure to do so is to exclude your testimony. Since the facts seem to indicate they don't need much, if any, of a statement to convict you; there's not really that much advantage for them to even spend the time questioning you.
By the way edit:
While Miranda tends towards the federal constitution, to make this right:
U.S. law only.