SPRINGFIELD, Ill. (AP) - Illinois now has the nation's strongest law protecting criminal defendants against self-serving jailhouse snitch testimony that has falsely put some people behind bars.

Lawmakers last month approved it over Gov. Bruce Rauner's veto. It requires judges in criminal trials to weigh the truthfulness of incarcerated informants' testimony before they testify.

Informants claiming they heard behind-bars confessions offer to testify against defendants in exchange for leniency or other benefits.

Chicago Democratic Rep. Arthur Turner and Tinley Park Democratic Sen. Michael Hastings sponsored the law to ensure such historically unreliable testimony is vetted before a jury hears it.

Since 1989, 19 Illinois defendants convicted in part by snitch testimony have been exonerated .

Prosecutors say they're already required to turn over to the defense information about informants and the benefits they're promised.