R.I. Gen. Laws § 5-5-21: Engaging in business without a license.

Whoever without a license engages in the general business of a private detective, or holds him or herself out as a private detective, or pretends to be a detective police officer, shall be punished by a fine of not less than two hundred dollars ($200) nor more than five hundred dollars ($500), or imprisonment in the adult correctional institutions not exceeding six (6) months, or by both fine and imprisonment. Nothing contained in this section applies to a detective of another state coming within this state in the performance of his or her duties, for a temporary period and on a specific matter.