When should a child be tried as an adult?

Good Morning.. very hard question. i just do not know, i think every case needs carefully looked at

a dear friend of mine had 4 sons, one hung around the wrong crowd. and got into some big trouble with involvement of a killing. the mom in the end felt like she did something wrong raising him. which she didnt the other kids are great. But she also said he should pay for his crime, no matter how much it hurted. because the person can never come back. this kid caused embaressment to the family, news, etc. they then moved and i never saw my friend again. where she is i dont know, but I do know she holds guilt in her for thinking she raised a monster. the boy was 16.
as far as younger kids?? I dont know, sometimes they get into trouble by trying to be cool, and it backfires.

my opinion is though even if they are little and they do something really bad, something should be done about it.

wow what a question , any time their is a child involved its sticky and all kids are brain dead and should not be held accountable for things they seem to make right in their minds . they live in fantasy land till their 25 yrs of age most the time and then they most generally regret what they've done. yes they think they know so much and some do how ever its like speeding recklessly down the road they do a lot and after 25 they think oh my god i could of killed myself about 30 they think of others. a lot of people think juvenile detention centers are fun and games how ever they are full of some of the most ruthless people alive and a lot of times their own parents may have influenced that and be the nicest , hard working people their is maybe something medical affected them at birth so the list can go on on so again what are we gonna do locking them up is wrong but if they dont respond to the general rules and laws of the land ??