The New Fairfield Resident Trooper's Office is reminding parents of a state law that makes it a crime for a parent, guardian or someone supervising a child to knowingly leave a child under the age of 12 years old in a motor vehicle or unsupervised in public for a length of time that creates a risk of harm to health and safety.  Troopers say even running into a business, daycare or elsewhere just for a minute is a danger.  If a child under 12 years old is watching another child under 12, Troopers say this also creates a significant safety risk. The guidelines indicate that in order for a juvenile to supervise younger children, they must be at least 15 years old.  The ages could be subject to interpretation based on child’s cognitive ability.