How do you take a 6 year old into custody?
The same way anyone else would be under arrest.
Do handcuffs even fit the wrists of a 6 year old.
Traditional cuffs; no. Flexcuffs; yes.
How do you question a 6 year old about a crime?
With parent or guardian present. Any LE entitity large enough to have a sex-crimes division has someone who's adept with dealing with kids.
Obviously where and how he got the gun is critical. If parents had a gun the kid could get his hands on the the parents should be in custody.
Agreed. If there is evidence of criminal intent or criminal negligence, in which case the parents would be seperately charged.
A six year old should always be under some kind of supervision. Parents, babysitter, teacher.
We're talking about a 1st grade child in the traditional sense. You'd have to define what "some kind of supervision" means. Developmentally, there are many things they can do without supervision, but a "follow up" is often warranted. For example, going to the bathroom. Or making a sandwich. Etc.
I don't think you let a 6 year old walk to school on his own. Not these days anyway.
Most don't, but some still do. I have a friend who lived behind his local suburban elementary, and they made their kids walk to school through the yard. And in some urban areas, the walk is very short; I have another friend in Chicago where they walk to school.
I think was concerns me (past the obvious horror of the topic) is how does a child that young gets enough rage AND intent, where he/she is now motivated to do such an act? This was a preplanned event; this took some amount of thinking. This wasn't a case of a child playing with a gun and accidentally shooting a sibling. This was murder; a killing with intent. A whole lot of other questions now arise. Is the child developmentally retarded, where a sense of right/wrong not present? Is the child develpmentally advanced, where these mature decisions are made? Is the child developmentally compromised; a psychopath? Etc, etc, etc ....