A unanimous Washington Legislature today sent Gov. Gary Locke legislation to lock up violent older teen criminals in adult prisons and get tougher with younger lawbreakers.

Capping years of discussions about how to combat youth crime and how to pay for it, the Legislature finally crafted an approach that won over every lawmaker. The Senate voted 45-0 for the plan, HB3900, this morning and the House followed suit 98-0.

In both houses, sponsors were emotional as they described the sometimes tense negotiations and the underlying concern of treating youths sternly when they commit violent crimes, yet compassionately as they are in the earlier formative years.

Locke, whose staff was part of the discussions leading to the legislation, is expected to sign the bill, which will cost an estimated $24 million in the coming two-year budget cycle beginning July 1, and $43 million in the following biennium.

Among its impacts will be to send an estimated 155 additional 16- and 17-year-olds a year into adult prisons, backers said. About 90 older teens now are jailed in the adult system each year.

“The system we have now simply doesn’t work,” House Law and Justice Chairman Larry Sheahan, R-Rosalia, said before he and five other conferees signed the bill. There are too many kids using guns to commit crimes and too many who think the system “is just a joke,” he said.

Others noted that along with tougher sentences, the measure contains programs for “early intervention” to steer young offenders away from crime, and programs to teach offenders to read and finish high school.