The Associated Press/Austin Daily Herald

RENO, Nev. -- After a five-day spate of pipe bombings that had rural Americans nervously eyeing their mailboxes, a cell phone signal and an alert motorist led authorities to their suspect: a 21-year-old college student who majored in art and sang in a punk band called Apathy.

Luke J. Helder, of Pine Island, Minn., was arrested Tuesday after a high-speed chase along a desert highway and a phone conversation with an FBI negotiator and his parents.

Authorities said Helder dropped a gun out his car window and was taken into custody without incident. At least one other gun was found in the car, authorities said.

After Helder surrendered, bomb squads called to the scene along Interstate 80 some 50 miles east of Reno dismantled five pipe bombs found in the car, said Maj. Rick Bradley of the Nevada Highway Patrol.

Early Wednesday, a handcuffed Helder was led into the Washoe County Jail by four federal agents. Wearing a black Kurt Cobain T-shirt and long, baggy tan shorts, his hair mussed, Helder was quiet.

"Luke, do you have anything to say to the media?" one reporter asked.

"No," Helder said, looking up. He answered the same way when asked if he had anything to tell his parents.

The capture came eight hours after the FBI issued an all-points bulletin for Helder and said it wanted to question him about the 18 pipe bombs found since Friday.

Six people -- four letter carriers and two residents -- were wounded by bombs left in mailboxes in Illinois and Iowa. Twelve other bombs found in Iowa, Nebraska, Colorado and Texas did not explode. Most of the bombs were accompanied by anti-government propaganda warning that more "attention getters" were on the way.

In response, authorities asked residents in several states to leave their roadside mailboxes open to give nervous letter carriers a clear look inside. That request was lifted Wednesday morning.

"We want to thank our customers for their wonderful cooperation during this difficult time," Postal Service spokesman Sam Bolen said.

Federal prosecutors in Iowa charged Helder with using an explosive to maliciously destroy property affecting interstate commerce and with using a destructive device to commit a crime of violence. The charges carry penalties of up to life in prison and fines of $250,000. In addition, he was booked on a federal firearms charge.

U.S. Attorney Charles W. Larson said Helder was responsible for cuts and shrapnel wounds suffered Friday by Delores Werling, 70, of Tipton, Iowa. Federal charges also were expected to be filed in Illinois, Larson said.

The FBI in Omaha, Neb., where the investigation was centered, refused to say how Helder had become part of the case.

But Menomonie, Wis., Police Chief Dennis Beety said Wednesday his department and the Dunn County Sheriff's Department both received calls about midnight Monday indicating Helder could be a suspect. He declined to say who the tipster was but said it was someone outside the Menomonie area.

Beety said the only law enforcement record he was aware of involving Helder was a city citation for possession of marijuana in October.

Helder was expected to go before a federal magistrate on Wednesday in Reno, where he is likely to be held for a few days before being transported to face charges, authorities said.

As the search for Helder intensified, his father was at the family's home about 60 miles southeast of Minneapolis and read a statement urging his son to call.

"I really want you to know that Luke is not a dangerous person," Cameron Helder said. "I think he's just trying to make a statement about the way our government is run. I think Luke wants people to listen to his ideas, and not enough people are hearing him, and he thinks this may help."

Helder was a junior majoring in art and industrial design at the University of Wisconsin-Stout, in Menomonie, Wis. Former classmates said Helder loved the grunge band Nirvana and was preoccupied with Cobain, its lead singer, who committed suicide.

Helder had not apparently attended classes since at least April 24, a school official said. He played guitar and sang in a punk-rock band called Apathy.

FBI agents searched Helder's apartment in a two-story building near campus. Menomonie police spokesman Brian Swantz said two houses nearby were evacuated because of "potential danger" but refused to elaborate.

After Helder's license plate and car description were broadcast nationwide Tuesday, a motorist on Interstate 80 spotted his vehicle and tipped off authorities. He was pulled over after a 40-mile chase that reached 100 mph.

"The FBI contacted him on his cell phone and started negotiations with him and asked us to back off," said Bradley. "Then he slowed down."

Authorities said Helder phoned his parents during the chase and was patched through to an FBI negotiator, then pulled over east of Fernley and volunteered to surrender if he was not harmed.

"He requested not to be tackled," Trooper Alan Davidson said. "He surrendered the gun and was taken into custody without incident."