Sex offenders who have attacked children in Alabama will have to undergo chemical castration as a condition of their parole after Governor Kay Ivey signed a bill into law Monday night that approved the new measure.

Under the law, offenders convicted of sex crimes with children younger than 13 will have to be chemically castrated before their release.

The treatment must begin at least a month before the release dates and continue until a judge decides that it’s no longer necessary.

The bill was introduced by Rep. Steve Hurst, a Republican, who said:

“If they’re going to mark these children for life, they need to be marked for life… My preference would be if someone does a small infant child like that, they need to die.”

“This bill is a step toward protecting children in Alabama,” Ivey said.

“They really misunderstand what sexual assault is about,” said Randall Marshall, executive director of the Alabama American Civil Liberties Union chapter.

“Sexual assault isn’t about sexual gratification. It’s about power. It’s about control.”

It says offenders must pay for the treatment, and they can’t be denied parole solely based on an inability to pay.

Both houses of the Alabama Legislature approved the legislation late last month after it was put forward by state GOP Rep. Steve Hurst.

The move has been strongly opposed by human-rights groups.