We're drifting a little here but since the question has been raised:
Good to know, thanks Trent.
Don't get me wrong - there are a LOT of decisions that go in to leaving a minor in charge of a firearm, and it's NOT something to be taken lightly, ever!
Under IL Law, we have the Child Protection act.
From the Illinois State Police website:
Will I be held responsible for my child who has access to a firearm?
Yes.
Illinois law (720 ILCS 5/24-9) states:
"(a) Except as provided in subsection (c), it is unlawful for any person to store or leave, within premises under his or her control, a firearm if the person knows or has reason to believe that a minor under the age of 14 years who does not have a Firearm Owners Identification Card is likely to gain access to the firearm without the lawful permission of the minor's parent, guardian, or person having charge of the minor, and the minor causes death or great bodily harm with the firearm, unless the firearm is: secured by a device or mechanism, other than the firearm safety, designed to render a firearm temporarily inoperable; or placed in a securely locked box or container; or placed in some other location that a reasonable person would believe to be secure from a minor under the age of 14 years.
(b) Sentence. A person who violates this Section is guilty of a Class C misdemeanor and shall be fined not less than $1,000. A second or subsequent violation of this Section is a Class A misdemeanor.
(c) Subsection (a) does not apply: if the minor under 14 years of age gains access to a firearm and uses it in a lawful act of self-defense or defense of another; or to any firearm obtained by a minor under the age of 14 because of an unlawful entry of the premises by the minor or another person."
Then we have this, from the same FAQ:
I am under the age of 21, do I need a FOID card?
Not necessarily. The FOID Act exempts unemancipated minors while in the custody and immediate control of their parent, legal guardian, or other person in loco parentis to the minor as long as their parent, legal guardian, or other person in loco parentis to the minor has a valid FOID card in their possession.
This also applies to ANY person babysitting your children. If ALL of your firearms are not locked up, your babysitter must have an FOID card.
But, this is a long topic and probably best reserved for a different thread, so I'll summarize.
The way the law is written, leaving a minor with access to weapons you can be charged with a crime
IF the minor causes death or great bodily harm to someone, unless it is in justifiable self-defense (which in IL means preventing death or serious bodily harm to you or another, another topic altogether..).
Federal and state law provide further restrictions on the possession of handguns if the person is under 21 and not accompanied by an adult (some would argue 18, but we're talking about Illinois, which restricts the TRANSFER of a handgun to someone under 21). Which is why I specifically said "long gun" earlier.
You DO have to consider "what if a friend of my child visits while you are away, gains access to a firearm, and uses it to shoot someone". In that case, you are criminally liable.
So the mindset, trustworthiness, and maturity of the minor comes in to play.
All of my children over 12 know where the firearms are, and how to operate them. I'd rather have my children alive and me in trouble, than my children killed by an intruder (which happened 30 miles from here a couple of years ago; all children in the house save the 3 year old were slain by an intruder, the 3 year old was life-flighted in critical condition and survived).
But this is a very personal decision. If you decide to allow a minor access to a firearm while you are away you have a VERY serious responsibility to provide high quality training to them, not just on safe and responsible use of firearms, but also a serious talk about justifiable lethal force.
Hearing a bump in the night is not justification to grab a gun and investigate. Firearms are for a LAST RESORT - an intruder is IN the house (or forcefully trying to break in) and intends to do harm.
It's a real touchy subject, for sure.