I am not normally in favor of tatoos, but it does seem that there is a parents’ rights issue here. More to the point, the little boy is grieving the sudden loss of his older brother. (And btw, his brother was hit by a car, not taken out by a gang or something. There doesn’t seem to be any reason to suppose that gangs or anything similar are involved here.) I think if one of my boys asked to memorialize his brother under similar circumstances, I would at least think about saying yet.
Ditto—in fact, this is probably the first instance I have heard of where I would favour a tatoo.