Gun store owners in southwestern border states argued in federal court Tuesday that the Obama administration cannot require them to report when customers buy multiple high-powered rifles.

The Justice Department responded to a lawsuit seeking to block the two-month-old requirement by asking a judge to uphold its legality, arguing the measure could help stop the flow of guns to Mexican drug cartels. It requires sellers in California, Arizona, New Mexico and Texas to give the Bureau of Alcohol, Tobacco, Firearms and Explosives information about purchasers who buy two or more semi-automatic rifles greater than .22 caliber within five days.

Justice Department attorney Daniel Reiss said having a database of multiple purchasers gives ATF agents the power to trace gun sales within minutes, rather than a multi-day effort to trace the weapons back through the manufacturer, to the seller and eventually the buyer. He said two investigations have already been opened in the short time that the new reporting has been required.

A court released the names of the jurors in the Casey Anthony trial for the first time Tuesday since they acquitted the Florida woman of murdering her 2-year-old daughter, Caylee.

The "cooling off" period a judge cited in delaying the release for three months ended Tuesday, and the names of 12 jurors and three alternates were released by the Pinellas County Clerk of Court.

After the trial ended in July, Judge Belvin Perry said he wanted time to pass before the names were made public because some of the jurors had received death threats.

Jurors were selected from Pinellas County, along Florida's Gulf Coast, because of concerns about pretrial publicity in Orlando. The jurors were sequestered until the verdict was announced.

Associated Press reporters knocked on doors Tuesday at homes where the jurors were thought to live.

The husband of alternate juror Elizabeth Jones answered the door at their home. He said she was at work. "I'll leave your card with the pile here," Mike Jones said. "But I don't think she is going to want to talk." He added that since she didn't deliberate, "she doesn't have a whole lot to say."

In most cases, the blinds or drapes were closed and no one answered. Dogs could be heard barking inside some of the homes.

An aspiring rapper on trial over what authorities say was a note threatening a Virginia Tech-like killing spree set off "alarm bells" days before the writings surfaced on his college campus by pressing to get firepower he ordered from a gun dealer, a prosecutor told jurors Wednesday.

But an attorney for Olutosin Oduwole countered during a trial's opening statements in the 4-year-old case that his gun-loving client stood wrongly accused, saying the words at issue were innocent lyrics and other musings by a performer prone to compulsively log all of his thoughts on paper.

"This case is a very selective case," Justin Kuehn said on behalf of Oduwole, accused of attempting to make a terroristic threat and a weapons count linked to the loaded handgun police found a short time later in July 2007 in Oduwole's on-campus apartment at Southern Illinois University in Edwardsville.

"That 'note' is nothing more than a piece of scrap paper with private thoughts, the beginning of a song," Kuehn insisted. "Their key piece of evidence, the center point of their case, is a song."

Wednesday's differing scenarios by the prosecutors and defense previewed testimony that could leave jurors with a key decision: Whether Oduwole's questioned writings — found in his out-of-gas car just months after the Virginia Tech rampage that left 32 people dead along with the gunman — represented something potentially sinister or were lyrical stylings that were constitutionally protected free speech.

Kuehn told the all-white jury that witnesses on Oduwole's behalf may include what the defense describes as an expert in the study of rap and hip-hop music, along with that genre's culture.

The trial's stakes are high: Oduwole, 26 and free on bond, faces up to 15 years in prison if convicted of the threat-related count.