R.I. Gen. Laws § 12-7-4: Arrest without warrant for felony.

A peace officer may, without a warrant, arrest a person for a felony, whenever:

(1) The officer has reasonable ground to believe that a felony has been or is being committed and that the person to be arrested has committed or is committing it.

(2) The person to be arrested in fact has committed or is committing a felony; and in that case it shall be immaterial that the officer did not believe him or her guilty or on unreasonable ground entertained belief in his or her guilt.