"I can confirm that some of the people arrested were part of the funeral," Champion family attorney Christopher Chestnut told ABC News Monday.
Chestnut also said several drum majors called Champion's mother after his death.
"We can't disclose who, but some of the drum majors reached out to her and although they experienced remorse and admitted to being present, their story just didn't add up," Chestnut said.
Champion, 26, was a member of FAMU's highly regarded "Marching 100" band when he collapsed and died Nov. 19 on a bus parked outside an Orlando hotel after a football game.
Last week, state prosecutors brought charges against 13 individuals.
He said learning some of those who took part in her son's funeral are now charged in his death has been difficult for Pam Champion.
"Is she surprised? No. Is she appalled? Yes," Chestnut said. "Was the initial call that appeared to be sincere really insincere? It has caused her to question many of the motives.
"It's shocking, but it isn't. What's even more shocking is the irony that it's not shocking because of who we're dealing with."
"This is the culture of hazing ... . I think it calls into question what exactly happened."
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