I feel like that map may be a little misleading. Just because a state doesn’t have a statutory age limit on treating a child as an adult doesn’t mean that is common practice. In most states, the default is that any crime committed by a suspect under the age of 18 is handled by the juvenile court system, where penalties are far less severe, unless some special nature of the crime prompts a court to try the accused as an adult (eg murder or violent rape). A few states set the juvenile cutoff a little earlier.