DULUTH, Minnesota — An attorney for six major music companies urged a federal jury Thursday to find a Minnesota woman liable for damages for illegally downloading and sharing music online, activity he said has gnawed at the industry's bottom line.

Record companies have filed some 26,000 lawsuits since 2003 claiming their music's been misused, but the case against Jammie Thomas, a mother of two from Brainerd, is the first to go to trial. Many other defendants settled by paying the record companies a few thousand dollars.

Regardless of how the first trial of a person accused of illegally sharing music online turns out, a spokesman for a record industry group said companies plan to keep suing listeners.

Richard Gabriel, the lead attorney for six companies that sued Thomas, didn't ask jurors to award a particular dollar amount or to find Thomas willfully infringed on copyrights.

"I only ask that you consider that the need for deterrence here is great," he said.

Thomas had testified that she did nothing wrong. Her attorney, Brian Toder, argued Thursday that music companies presented plenty of technical evidence but never proved that "Jammie Thomas, a human being, got on her keyboard and sent out these things."

"We don't know what happened," Toder told jurors. "All we know is that Jammie Thomas didn't do this."

Gabriel called such assertions "misdirection, red herrings, smoke and mirrors."

The record companies' evidence included testimony that sought to link Thomas to a Kazaa file-sharing account that held the copyrighted material. Thomas testified that she never had a Kazaa account, but acknowledged giving conflicting dates for the replacement of her computer hard drive — something Gabriel suggested was done to cover her tracks.

The companies are seeking damages regarding 24 songs the trial focused on, not the 1,702 that were described in their complaint.

The 12-member jury must agree unanimously. If they decide Thomas infringed on the record companies' copyrights, they will then consider whether she did it willfully — a distinction that could drive maximum damages from $30,000 per song as high as $150,000 per song.

US District Judge Michael Davis ruled Thursday that the record companies did not have to prove songs on Thomas's computer were transferred to other users for her to be found liable. The act of making the files available would constitute copyright infringement, he said.

Cary Sherman, president of the Recording Industry Association of America, which coordinates the lawsuits, said companies will keep filing them.

"We think we're in for a long haul in terms of establishing that music has value, that music is property, and that property has to be respected," said Sherman.

Sherman said Wednesday night that he's surprised it took this long for one of the industry lawsuits to go to trial.

After four years, he said, "it's become business as usual, nobody really thinks about it. This case has put it back in the news. Win or lose, people will understand that we are out there trying to protect our rights."

The record companies involved in the lawsuit are Sony BMG, Arista Records LLC, Interscope Records, UMG Recordings Inc., Capitol Records Inc. and Warner Bros. Records Inc.