TUCSON — A judge declared a mistrial in U.S. District Court on Tuesday when jurors were unable to reach a verdict for a U.S. Border Patrol agent charged with murdering an illegal immigrant from Mexico.

Nicholas Corbett was charged with second-degree murder, manslaughter and negligent homicide in the death of Francisco Dominguez-Rivera near Naco on Jan. 12, 2007.

He went on trial in February and March, but that jury also was deadlocked and a mistrial was declared.

The second trial started Oct. 21. The jury, made up of seven men and five women, deliberated for about 17 hours over the course of four days.

On Monday, the jurors wrote a note to the judge indicating they were deadlocked.

The judge told them to continue deliberating.

On Tuesday afternoon, jurors sent another note to the judge indicating they were still at an impasse.

Sean Chapman, the lead defense attorney representing Corbett, asked Judge David Bury to declare a mistrial. Cochise County Attorney Ed Rheinheimer did not object to that request.

The jurors came into the courtroom and the panel’s foreman told the judge he believed additional deliberations would not produce a verdict. Bury declared a mistrial.

The contents of the jury’s notes sent to the judge were not disclosed. The judge is considering sealing it because it contains information that is not supposed to be publicly disclosed.

During an interview after the mistrial was declared, Jim Calle, the assistant defense attorney, said his understanding was the jury was deadlocked at a vote of 11-1, with the majority deciding to acquit Corbett. However, Rheinheimer said that vote may or may not be accurate.

The Wick News Service attempted to interview some jurors as they left the courthouse, but they declined to make any statements.

Corbett declined to comment. Chapman said he is disappointed the jury did not acquit Corbett. If necessary, he said, he will represent him if the case goes to trial again.

The Border Patrol Union in Tucson claims on its Web site that Rheinheimer advised the press that he will not retry the case. However, Rheinheimer told the Herald/Review he plans to review the case before making an official decision on the matter.

Rheinheimer also said he was disappointed the jurors did not decide on a verdict. He pointed out that during the first trial, the jury was deadlocked at a vote of either 10-2 or 11-1, with the majority in favor of a conviction.

The Border Patrol Union’s Web site proclaimed that “this nightmare is now over, for good.”

“This was worth every penny we spent defending agent Corbett, and we were proud to help him. We have believed in his innocence from the first day, and we never doubted him. He should hold his head high and be proud of himself for the job he has done protecting this country,” the site states.

Jennifer Allen, executive director of Border Action Network, a human rights group in Tucson, said it is “astounding” the jurors could not convict Corbett and could not support an illegal immigrant.

“Even in the face of overwhelming evidence, people want to believe so hard that Border Patrol agents uphold high ethical standards,” she said. “In this case, Corbett didn’t do that. In this case, he murdered Francisco Dominguez-Rivera. He needlessly killed him.”

Prosecutors alleged Corbett killed Dominguez-Rivera without justification as he was surrendering. The defense maintained Corbett shot the victim to defend himself from a rock during hand-to-hand combat.