according to the child welfare information gateway, myland is one of those states along with illinoisnd oregon. >> maryland state laws say at age 8 you're allowed to be home alone. montgomery county police say age isn't the only factor. parents need to be certain their child is mature enough to be left alone without causing stress. >> i wouldn't leave her alone until she was quite a bit older. e would want to impress me by baking cookies and i don't want her using the oven. >> when they hear a knock at the door -- >>'t i dare who knocks at the door, i don't care what thet say, w they're selling, do not open the door. >> what happens if there's a police oicer at your door. what should your child do? the child should feel comfortable askingm to show a badge or i.d. and parents can take their kids to a police station to find out what a rl i.d. looks like. i'd tell my kids not to open the door. >> ifhere's a knock, it's not for you. i have a key. >> exactly. i tell them not to go to the door. >> we also reached out to law enforcement in virginia and d.c. both say they have home alone reco