Prosecutors will begin giving out letters to some undocumented witnesses and victims that could potentially shield them from deportation, Travis County District Attorney Margaret Moore said Thursday.

The letters declare the person “a crime victim and/or essential witness in a felony case currently pending in Travis County" and needed for the prosecution of a case.

“The idea is that, if they are picked up by law enforcement to be turned over to ICE, they would be able to present this letter," she told KUT's Trey Shaar. "And the request in the letter is for the law enforcement person to verify, to call us and let us know they have that person, so we can take appropriate steps.”

Moore said her office came up with the idea, which was first reported by the Austin American-Statesman, in response to policy changes from the Trump administration and in anticipation of Texas' new law banning so-called “sanctuary” policies.

The law, which goes into effect Sept. 1, allows law enforcement to ask about a person's immigration status during a routine detainment, like a traffic stop. Interim Austin Police Chief Brian Manley, Mayor Steve Adler and others have said it could deter victims and witnesses from coming forward to report crimes.

"We also want victims and witnesses to feel comfortable coming forward, so maybe this will help with that," Moore said.

She said federal immigration policy is not to interfere with prosecutions, and people cooperating in a felony case are eligible for visas. The letters would be an interim measure ahead of a victim or witness being granted a visa, she added, typically after a case is prosecuted.