Americans need to know more about undocumented immigrants' crime activity, argues U.S. Rep. Mo Brooks, who introduced a bill Wednesday that would require law enforcement to keep track of such crimes. Under the Arrest Statistics Reporting Act, state and local authorities would be forced to provide the immigration status of suspects in arrest reports and the FBI's annual reports would include undocumented immigrant crime.

Brooks, of Alabama, said these provisions are necessary because the government does not publicly report state and local illegal immigrant crime data, "thus undermining our understanding of how bad the illegal alien crime problem is and what we must do to address it." In a floor speech presenting the bill, Brooks cited U.S. Sentencing Commission data, saying that undocumented immigrants committed 74 percent of federal drug possession crimes, 20 percent of kidnapping and hostage-taking cases, 17 percent of drug trafficking crimes and 12 percent each of money laundering and murder cases.

But he said the data does not provide a full enough picture. "The absence of state and local law enforcement data is critical because most heinous crimes, such as murder, rape, violent assaults, and the like, are prosecuted at the state level," he said.

Both sides of the immigration debate have tried to find data to support their positions after GOP presidential candidate Donald Trump made controversial remarks at his campaign launch last month. “When Mexico sends its people, they're not sending the best,” he said during the announcement. “They're not sending you, they're sending people that have lots of problems and they're bringing those problems. They're bringing drugs, they're bringing crime, they're rapists... and some, I assume, are good people, but I speak to border guards and they're telling us what we're getting."

The issue has also garnered national attention recently after an undocumented immigrant allegedly shot a woman to death July 1 in San Francisco. The suspect, Juan Francisco Lopez-Sanchez, is a seven-time felon who had been deported to Mexico five times but was previously released from San Francisco Sheriff's Department custody -- against ICE's request for him to be held until he could be transferred to a federal facility --  prior to the fatal shooting of Kate Steinle. Lopez-Sanchez eventually pleaded not guilty to the charge.