When finalized, a recent amendment to the Violence Against Women Act, will allow federal agents to collect DNA samples from anyone placed under criminal arrest.  Until now, sampling was permitted only from convicted felons.

"Under the new law, DNA samples would be taken from any illegal immigrants who are detained and would normally be fingerprinted, justice officials said. Last year federal customs, Border Patrol and immigration agents detained more than 1.2 million immigrants, the majority of them at the border with Mexico. About 238,000 of those immigrants were detained in immigration enforcement investigations. A great majority of all immigration detainees were fingerprinted, immigration officials said. About 102,000 people were arrested on federal charges not related to immigration in 2005.

The law has strong support from crime victims’ organizations and some women’s groups, who say it will help law enforcement identify sexual predators and also detect dangerous criminals among illegal immigrants."

Source: NY Times

A few more excerpts from the same NY Times article: 

“Obviously, the bigger the DNA database, the better,” said Lynn Parrish, the spokeswoman for the Rape, Abuse and Incest National Network, based in Washington. “If this had been implemented years ago, it could have prevented many crimes. Rapists are generalists. They don’t just rape, they also murder.”

“Whereas fingerprints merely identify the person who left them,” Mr. Neufelda, a lawyer who as a co-director of the Innocence Project ans has helped exonerate dozens of inmates using DNA evidence said, “DNA profiles have the potential to reveal our physical diseases and mental disorders. It becomes intrusive when the government begins to mine our most intimate matters.”

-tdm