95% of warrants for murder in Los Angeles are for illegal aliens.
This figure also appears (unsourced) in Heather Mac Donald's testimony before the House Judiciary Subcommittee on Immigration, Border Security, and Claims:
In Los Angeles, 95 percent of all outstanding warrants for homicide in the first half of 2004 (which totaled 1,200 to 1,500) targeted illegal aliens. Up to two-thirds of all fugitive felony warrants (17,000) were for illegal aliens.
Even if the statistic is accurate, however, it is subject to a variety of interpretations. For example, illegal aliens might be disproportionately represented by outstanding homicide warrants in Los Angeles because they are more likely to flee the jurisdiction before their cases are adjudicated than legal residents are (not necessarily because they commit a far greater share of the homicides in Los Angeles). This interpretation is supported by a University of California Davis summary of immigration issues that notes:
The Los Angeles Police Department has a 12-year old Foreign Prosecution Unit that pursues suspects who fled the US after committing crimes in Los Angeles and gives testimony when they are prosecuted aboard. The United States does not have extradition treaties with most Latin American countries but many countries, for example, Mexico, Nicaragua or El Salvador try suspects for murder and other violent crimes committed in the US.

The Foreign Prosecution Unit was founded in 1985, after a study found that nearly half of the LAPD's outstanding arrest warrants involved Mexican nationals who were presumed to have fled the country. The FPU works with Interpol to find suspects who flee abroad and then prepares the evidence so that the person can be arrested and prosecuted. The FPU clears about one-third of its cases, compared to two-thirds of all homicide cases in Los Angeles.

The Mexican consulate in Los Angeles has a representative of the Mexican attorney general's office to work with the FPU in prosecuting suspects in Mexico for crimes committed in Los Angeles.
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