Grand Rapids police arrested a 17 year old boy and intend to charge him as a grownup. 

The teen took off running when he was seen near the Alexander Elementary School after midnight this morning. 

The cops say they chased him several blocks south and into a house on Hancock, SE, where they also found sawed-off shotguns and more handguns. 

WOOD TV says the youth faces at least one concealed weapons charge from this incident.