Antonio Ross, 27, allegedly assaulted the special education student in 2009, and later was charged with kidnapping and unlawful restraint in another case this year, the Chicago Tribune said Monday.
In January, Ross was charged with criminal sexual assault and aggravated criminal sexual abuse in the 2009 case, and later charged with kidnapping and unlawful restraint in this year's incident. He has been in the Cook County Jail since Feb. 1 in lieu of $750,00 bail, the newspaper said.
Angry parents said Ross should never have been allowed back on a school bus while the first incident was under investigation.
"It just made me angry as a parent," said the unidentified mother of the girl in the second incident. "You are transporting kids around -- that is what your company does. I think they should not have had him operating a bus until it was resolved."
Ross worked for Jewel's Bus Co. and is related to the family of the company's president, the Tribune said.
School officials said they contract bus services to private companies and largely depend on them to ensure their employees are safe.
The Tribune did not name the mother of the girl allegedly assaulted, but said she has sued Ross, Jewel's Bus Co. and her daughter's school.
Bus company president Jewel Lockhart declined to comment on the case and Ross maintains his innocence.