AUSTIN — The Texas Senate yesterday passed a bill targeting sexual predators that includes a possible death penalty for those who are twice convicted of raping children under 14.“I can think of no more solemn duty than the protection of our most innocent and vulnerable citizens,” said state Senator Bob Deuell, who sponsored the measure.

Texas already has the most active death row in the United States.

If the bill becomes law, Texas would be the sixth state to allow some child sex offenders to be sentenced to death. The others are Florida, Montana, Louisiana, Oklahoma and South Carolina.

To become law, lawmakers from the state Senate and House must agree on a version of the bill, and Governor Rick Perry must approve it. Perry has called the passage of a child sex offender bill a legislative emergency. The House has approved a different version of the bill.

The bill creates new categories of sexually violent offences against children under 14, including categories for crimes committed involving kidnapping, date-rape drugs and deadly weapons. Such crimes, or any aggravated sexual assault on a child under 6, automatically carry a minimum sentence of 25 years in prison.

A second offence of those crimes could carry the death penalty.

Critics have asked whether the death penalty in cases where the victim does not die would be unconstitutional. In 1977, the US Supreme Court threw out the death penalty in a Georgia rape case. Louisiana has one inmate on death row in a child sex crime, but the case is still subject to appeals in state and federal courts.