The Arizona Senate approved a proposal intended to combat the forced marriages of teenage girls in polygamist enclaves.
The full Senate voted 29-0 Monday to create the crime of child bigamy. The bill (SB1335) now moves to the House.
Modeled after a Utah law, the legislation would make it a felony for a married adult to marry a child or otherwise cohabit as husband and wife with a child.
It also would make it illegal to arrange marriages or cohabitation under those circumstances.
Polygamy is practiced openly in Colorado City, a remote enclave on the state line with Utah that is dominated by the Fundamentalist Church of Jesus Christ of Latter Day Saints.
The sect split from mainstream Mormonism after the broader church renounced polygamy more than a century ago. The fundamentalist group touts plural marriage as a key to reaching the highest place in heaven.
The Utah law was used to prosecute polygamist Rodney Holm, a former police officer in Colorado City and neighboring Hildale, Utah.
A Utah jury convicted Holm of bigamy and unlawful sexual conduct with a minor 16 or 17 years old due to his union with his third wife, who was 16 when they married.