(CNN) -- The mother of Florida A&M University drum major Robert Champion said Wednesday she had been hoping more severe charges would be filed in her son's death, which authorities said was the result of hazing.
Pam Champion told "AC360" that hazing, which prosecutors said is a term for bullying, doesn't amply describe what happened to her 26-year-old son.
"The term 'hazing' in itself is a very light term," she said. "I don't look at it as being a form of bullying. Hazing is a very brutal assault ... against another person."
Charges were brought against 13 people after an investigation into Champion's death, a Florida prosecutor announced Wednesday.
Medical examiners said Champion died "within an hour of a hazing incident during which he suffered multiple blunt trauma blows to his body."
"This is a homicide by hazing," State Attorney Lawson Lamar said in Orlando.
The case built by investigators does not support a charge of murder, according to Lamar.
"We can prove participation in hazing and a death. We do not have a blow or a shot or a knife thrust that killed Mr. Champion. It is an aggregation of things, which exactly fit the Florida statute as written by the Legislature," Lamar said.
Pam Champion said prosecutors explained why they pursued hazing charges, rather than murder or manslaughter. She and her husband, Robert Champion Sr., were anticipating "something that was a little more harsh."
Eleven individuals each face one count of third-degree felony hazing resulting in death, according to officials. Each one also is accused of two counts of first-degree misdemeanor hazing. State law provides a prison term of up to six years for those facing the more serious charges, Lamar said.
Two people each face a single count of misdemeanor first-degree hazing. Sentences in such cases typically call for up to a year in jail.
Some of the charges involved two other alleged hazing victims who were not seriously injured, officials said.
"It's all related to the same investigation that began with Robert Champion," said Danielle Tavernier, a spokeswoman for the state attorney's office. "Investigators found these two victims during the course of investigating the death of Mr. Champion."
The drum major collapsed in Orlando on a bus, which was carrying members of FAMU's Marching 100 after a November 2011 football game that included a halftime performance by the group.
Champion's death more than five months ago brought renewed public scrutiny to hazing, a practice that has gone on for years. FAMU said it has taken steps to eradicate the problem.
Authorities declined to identify those who had not been arrested.
Two suspects were being held Wednesday afternoon at the Leon County Jail, according to Lt. James McQuaig, spokesman for the Leon County Sheriff's Office. The suspects were identified as Caleb Jackson, 23, and Rikki Wills, 24. Both are charged with felony hazing resulting in death. FAMU is in Tallahassee, the county seat.
Joyce Dawley, the head of the Florida Department of Law Enforcement's Orlando division, said one person was being sought out of state.
Attorney Christopher Chestnut said the Champions don't want to see the futures of students destroyed, but "they want accountability for the murder of their child."
Some university band members have said Champion died after taking part in an annual rite of passage called "Crossing Bus C," an initiation process in which pledges attempt to run down the center aisle from the front door of the bus to the back while being punched, kicked and assaulted by senior members.
An autopsy found "extensive contusions of his chest, arms, shoulder and back," as well as "evidence of crushing of areas of subcutaneous fat," which is the fatty tissue directly under the skin.
The Champions filed a lawsuit this year accusing the bus company and the driver of negligence. An estimated 30 people were on the vehicle.
Fabulous Coach Lines President Ray Land said before the suit was filed that the company's employees, who were not on the bus at the time, responded quickly after learning that there was an emergency, even following the ambulance transporting Champion to the hospital.
The school's band director, meanwhile, asked for full reinstatement Wednesday.
An attorney for Julian White, placed on paid administrative leave shortly after Champion's death, said White worked to root out hazing over 22 years as director.
"Dr. White remains disappointed that barely 48 hours after meeting with band members that Robert Champion was killed in an extreme, horrific and illegal act of bullying," White's attorney, Chuck Hobbs, said in a statement.
The death prompted the university board of trustees to approve an anti-hazing plan that includes an independent panel of experts to investigate.
"We are vigorously working to eradicate hazing from FAMU and doing everything within our power to ensure an incident like this never happens again," President James H. Ammons and Solomon Badger, chairman of the trustees, said in a statement issued Wednesday. "Our hearts and our prayers are with the Champion family and the extended FAMU family as we all continue to deal with this tragedy."
Lamar said Champion's death was "nothing short of an American tragedy."
"No one could have expected that his college experience would include being pummeled to death, an event that some, early on, mistakenly called a rite of passage," he said.
CNN's George Howell and Vivian Kuo contributed to this report.