Inmate advocates worry that a proposal to reduce the financial penalties for states that don't comply with a 2003 federal law aimed at eliminating rape behind bars will severely damage it.

The measure failed this fall. Its sponsor, Sen. John Cornyn, R-Texas, vows to re-introduce it in the new GOP-controlled Congress.

Cornyn said the funds include grants for worthy programs — such as ones that support rape and domestic violence victims — and that the law should be more narrowly tailored to affect money that goes to prison construction, operations and administration.

Supporters of the measure acknowledge the change would essentially eliminate the financial penalties, since little — if any — federal grant money is used for prison construction, daily operations and administration.

Those costs are typically handled by local government budgets.

A LONG-IGNORED PROBLEM: PRISON RAPE

Inmate advocates had lobbied for years for policymakers and lawmakers to address the problem of prison rape. Federal statistics show about 216,000 adult and juvenile inmates are sexually assaulted each year, compared to 238,000 in the overall U.S.

More than half of all sexual assaults behind bars are committed by prison staffers, according to the U.S. Department of Justice, and more than half of those employee-on-inmate assaults are committed by women.

Among the most vulnerable populations are the mentally ill, juveniles and lesbian, gay, bisexual and transgender inmates.

ATTITUDES BEGIN TO CHANGE IN THE 1990s

By the mid-1990s, more than half of the states passed laws defining staff-on-inmate sexual misconduct as a criminal offense.

And in 1994, the U.S. Supreme Court ruled that federal prison officials in Terre Haute, Indiana, failed to take reasonable measures to protect a transgender woman who was repeatedly raped after she was sent to live with the general male population.

A UNANIMOUS VICTORY

Prison rape survivors, inmate advocacy groups and evangelical organizations lobbied Congress to pass a law that aimed to end sexual assault behind bars. In 2003, Congress unanimously passed it.

The law's requirements ranged from increased training of staff about sex abuse policies to screening new inmates to determine if they're likely to commit sexual assault or to be assaulted.

If states opt out of the law or don't comply, they stand to lose 5 percent of federal funds they get for prison operations.

$110 MILLION, AND CHANGE

In all, states have spent more than $110 million in state and federal funds to implement the law. By last fall, every state was supposed to certify that it had instituted dozens of the standards.

So far, New Jersey and New Hampshire say they are compliant with the law's requirements, and 43 states and the District of Columbia are working toward that goal. All states have made some improvements to follow the law.

Pennsylvania developed a web-based incident reporting program, and is working to improve prosecution strategies to ensure that rapists are brought to justice. Colorado and Oregon, for example, are using software to help track sexual assault reports.

SOME STATES OPT OUT, CITING COST, AUTONOMY

Texas, Arizona, Florida, Indiana, Nebraska, Utah and Idaho have opted out, arguing that it's too costly to implement requirements that they say don't give them the flexibility to administer their facilities the way they see fit.

Texas, for example, says a requirement to prevent guards from seeing inmates of the opposite sex naked in the showers or during strip searches wouldn't work because 40 percent of the correctional officer workforce is female.

TOO EARLY TO SAY IF LAW IS WORKING

Federal surveys show the nation's rate of sexual victimization behind bars has remained steady for at least 7 years, with nearly 1 in 10 adult inmates reporting attacks. The rate is the same for juveniles, although that has improved slightly since 2008.