Washington ( CNN ) -- President Barack Obama on Thursday signed the Tribal Law and Order Act , which provides greater law enforcement powers for tribal authorities on Indian reservations . At an emotional White House ceremony , Obama comforted a rape victim who broke down while trying to introduce him , by coming out early and offering her reassurance as she struggled to tell her story . Lisa Marie Iyotte of the Rosebud Sioux Tribe wept openly in describing the assault in 1994 by an attacker who was later convicted of another rape , but never prosecuted for the crime against Iyotte . Obama said the law he was signing would help prevent something like that from happening . Crime rates on some Indian reservations are 20 times higher than the national average , Obama said , adding that one in three Native American women are raped in their lifetimes , which he called `` an assault on our national conscience . '' `` These are significant measures that will empower tribal nations and make a real difference in people 's lives , '' Obama said of the new law . The law requires the Department of Justice to improve coordination with tribal justice officials in prosecuting crimes on reservations , and provides resources for better overall cooperation between tribal , state and federal agencies . In addition , the measure increases the maximum sentence that tribal courts can impose to three years , instead of the previous limit of a one-year sentence . Supporters of the measure say the sentencing provision will expand the number of cases handled by tribal courts , increasing local tribal control on reservations . The new law reauthorizes existing initiatives such as at-risk youth programs and treatment programs , said Jefferson Keel , president of the National Congress of American Indians . `` Law enforcement on tribal lands has long been hamstrung by a lack of resources and by restrictions placed by the federal government , '' Keel said . `` The Tribal Law and Order Act is a significant step forward for tribal police . '' The House approved the bill last week ; it passed the Senate in June .
NEW : President Obama signs the Tribal Law and Order Act . NEW : Chief comforts rape victim who breaks down while comforting him . The new law limits law enforcement powers of tribal governments . Statistics : One in three Native American women are raped .