Federal charges brought against accused mailbox bomber

Helder arrives at the Federal Courthouse in Cedar Rapids, Iowa, Friday.

CEDAR RAPIDS, Iowa (CNN) -- Mailbox bomb suspect Lucas Helder arrived Friday night in Cedar Rapids, Iowa, and appeared in federal court to face charges of planting homemade bombs in mailboxes in five Midwestern states.

Helder did not speak at the six-minute hearing, during which U.S. District Judge John A. Jarvey read two charges: malicious destruction of property by means of an explosive and using a destructive device in a crime of violence.

Jarvey also appointed a public defender, Jane Kelly to represent Helder and set a preliminary hearing for May 22.

The 21-year-old college student appeared drawn and fatigued. Wearing a white jumpsuit, he conferred several times with his attorney.

EXTRA INFORMATION Map: Bombing sites    Federal charges against Helder Illinois Use of an explosive to maliciously destroy property Use of a destructive device to commit a crime of violence (Read the criminal complaint -- PDF) Iowa Use of an explosive to maliciously destroy property affecting interstate commerce Use of a destructive device to commit a crime of violence (Read the criminal complaint -- PDF) Nebraska Interstate transportation of explosives (Read the criminal complaint -- PDF) Nevada Possession of a firearm in the commission of a crime  Helder background Name: Lucas John Helder Age: 21 School: University of Wisconsin-Stout Class: Junior Major: Art/industrial design Hobbies: Guitar, Internet Favorite band: Nirvana

The charges in Cedar Rapids are the first of several federal charges connected to Helder's bombs, which wounded six people.

Helder's cross-country bombing spree ended Tuesday with a 40-mile high-speed chase across a Nevada desert highway. Behind him were 18 pipe bombs in five states, six of which exploded, wounding four postal workers and two Iowa residents.

In the trunk of his father's car, which Helder was driving when he was caught, were six more bombs. According to affidavits filed in court, the University of Wisconsin-Stout junior has admitted planting the bombs.

'Crime of violence' charge

A two-count criminal complaint was filed Tuesday in federal court in Iowa, charging the student with using bombs to maliciously destroy property and to "commit a crime of violence" that injured a woman in rural Tipton. (Read the charges in Iowa -- FindLaw PDF)

Conviction on that offense could result in a life prison sentence.

Similar federal charges were filed against him in Illinois. (Read the charges in Illinois -- FindLaw PDF) In Nebraska, he faces another federal charge of interstate transportation of explosives. (Read the charges in Nebraska -- FindLaw PDF) In Nevada, he faces a federal charge of possession of a firearm in the commission of a crime.

During a Wednesday court appearance for the clean-cut college student and one-time rock band member, Assistant U.S. Attorney Craig Denney said police seized a shotgun loaded with a single round from Helder's car.

Denney said the suspect told authorities he purchased the gun intending to take his life.

Helder was identified Monday when his father contacted authorities in Menomonie, Wisconsin, where his son attended school. Cameron Helder told Menomonie police he'd received a phone call from Lucas that led him to believe the young man might be the mailbox bomber who began a weekend of bombs and bomb scares last Friday in Illinois and Iowa.

Helder's parents, Pamela and Cameron Helder of Pine Island, Minnesota, looked grim and harried when they visited him in the Nevada jail Thursday, a day before his scheduled transfer to Iowa.

Cameron Helder, the young man's adoptive father, thanked the FBI and the Washoe County, Nevada, Sheriff's Department "for making this visit with Lucas possible so that we have a better understanding of what's going on in his mind."

But the Helders and others who knew Lucas expressed bafflement over his admitted behavior, and at times Lucas himself appeared not to understand the impact of what he had done.

Helder allegedly left behind anti-government messages with each of his bombs, and allegedly mailed a letter to the University of Wisconsin-Madison school newspaper that appeared to justify the bombings as a way to get attention for his views.

The bulk of the problems, the letter said, could be traced to government intervention in individual lives and the government encouraging people to fear death, which the writer said does not exist.

The writer said he did what he did to help, adding that he was only doing it to help, "taking very drastic measures in attempt to provide this information to you."

At a hearing in Reno, U.S. District Judge Robert McQuaid agreed with the prosecutor that Helder should be detained without bond, saying he posed a danger to the community and an escape risk, despite defense pleas that he be released to the custody of his family.

The judge said he believes Helder "suffers from some apparent mental health problems."

-- CNN correspondents Charles Feldman and Martin Savidge and Producer Mike Ahlers contributed to this report.