Family/Kids Movie

A movie about a kid called nathan who witnessed a crime and he was the only witness, he found a key near the crime scene and he took it, then the police took the boy to investigate with him but first , they sent him with a co called roman to stay at his house for two days, but the kid ran away and went to the key adress he found and found out that the key is for a closet whuch has alot of money inside and he makes trouble with the cop roman , roman likes a piano teacher called tresh and that’s all I remember please help me if you the name of the movie or the name of the actors.