At a congressional hearing billed as the first-ever focused on ending the “school-to-prison pipeline,” Edward Ward emerged as a voice of experience.

Ward, a recent high school graduate from Chicago, recalled classmates suspended for failing to wear ID badges and security officers patrolling hallways. Arrests were so common that a police processing center was created on campus “so they could book students then and there,” he said at the hearing Wednesday.

Suspended students “would disappear for days,” Ward said, “and when they got kicked out, they would disappear for weeks.” He recounted the story of a cousin suspended so many times he dropped out.

Even as an honor student, Ward said, “I felt constantly in a state of alert, afraid to make even the smallest mistake.”

Ward testified about the violence and poverty of his neighborhood and the harshness of his school in a Senate hearing room crowded with students, parents, lawyers, educators and activists from Washington and far beyond — 250 people in all, with another 150 people in an overflow room.

It was a defining moment for the issue, which advocates call the school-to-prison-pipeline. It refers to get-tough disciplinary practices that steer students out of schools — through suspension, expulsion or police involvement — and into the criminal justice system.

Lately, the phenomenon is getting more attention.

On Wednesday, two administration officials, two congressmen and a panel of five experts — including Ward — described the problem, offering figures and studies, individual experiences and ideas for change.

More than 3 million students each year are suspended or expelled from school across the United States. Federal data, though limited, show that more than 240,000 students were referred to law enforcement.

“For many young people, our schools are increasingly a gateway to the criminal justice system,” said Sen. Richard J. Durbin (D-Ill.), chairman of the Senate Judiciary Committee’s subcommittee on constitution, civil rights and human rights, as he opened the hearing. “What is especially concerning about this phenomenon is that it deprives our kids of their fundamental right to an education.”

Durbin and others attributed much of the problem to the surge of zero-tolerance policies and police presence that took hold in schools in the 1990s and increased in the aftermath of the massacre at Columbine High School in 1999. “A schoolyard fight that used to warrant a visit to the principal’s office can now lead to a trip to the booking station and a judge,” Durbin said.

The tough discipline of recent years has fallen hardest on African American and Hispanic students, federal figures show. In many cases, minor misbehavior that could be handled in other ways results in suspensions or worse, witnesses said.

“Police are arresting students for behaviors like talking back — that’s disorderly conduct. Or writing on desks — that’s vandalism,” said Judith Browne Dianis, co-director of the Advancement Project, a civil rights organization long active on the issue.

Assistant Education Secretary Deborah Delisle noted that African American students are more than 31 / 2 times as likely to be suspended or expelled as their white peers. Students with disabilities are twice as likely to be removed as non-disabled peers.

“It raises substantial concerns,” she said, citing the case of a black kindergartner who drew a five-day suspension for setting off a fire alarm, while a white ninth-grader facing the same infraction in the same district was suspended for one day.

Melodee Hanes, acting administrator of the Justice Department’s Office of Juvenile Justice and Delinquency Prevention, said the pipeline could be summed up as “the pervasive use of court referrals as a means of disciplining kids in school.”

She and others pointed to a landmark 2011 study in Texas, which found that suspensions were pervasive and that, after their first suspension, students were nearly three times more likely to be involved in the juvenile justice system the next year. The study examined records for nearly a million school children.

Research shows what is at stake, Hanes said. “We have learned that the minute a child sets foot in the juvenile justice system, their chances of becoming an adult offender go up 50 percent,” she said, adding that odds diminish for those students completing school and landing a good job.

Witnesses talked about strategies for change, such as positive behavior approaches in schools and restorative justice programs. Several said that they do not blame teachers and principals but that school leaders need more tools to manage behavioral issues.

Steven Teske, chief judge of the juvenile court in Clayton County, Ga., described how zero-tolerance policies have sent hundreds of students to his courtroom and how he has led a community effort that has become a national model for change.

“This issue is not going away,” Teske said. “It’s here to stay until the pipeline’s dismantled.”

When the hearing ended, Ward, a sophomore at DePaul University in Chicago, was hopeful and thought of students he has known over the years. “When you suspend a student,” he said, “they are forced back on the streets again.”