Investigators say they've identified at least seven victims of abuse, with ages ranging from young girls 2 or 3 years old to a pair of adult women. All of the alleged victims are female and most are between 2 and 13 years old.
"This is probably the worst of the worst," said police Sgt. Brian Loyd, who has investigated child abuse cases for 22 years. "Several of these children were abused multiple times."
Carroll's attorney, Roy Minton, did not immediately return a telephone message left at his office seeking comment Friday.
Some of the tapes appear to date to the 1980s and others appear to be within the last two years, police said.
According to an arrest affidavits, a videotape seized from Carroll's home shows him sexually assaulting a 6-year-old girl in 23 instances. The women appeared to be unconscious when they were assaulted. They didn't know about it until contacted by police, Loyd said.
Loyd said police expect to find more victims and to file more charges, but refused to release many details of their investigation.
A successful businessman, Carroll founded of a court-reporting service with offices in Austin, San Antonio and Houston. He also volunteered to aid with disaster relief programs. In 2004, he began volunteering time with the Court-Appointed Special Advocates of Travis County.
"He was the perfect neighbor, the perfect friend," Loyd said.
While most of the identified victims were children of Carroll's friends and not connected to the CASA program, one 8-year-old girl was in a family that adopted children Carroll had worked with, Loyd said.
"He maintained a relationship with the family," Loyd said.
Carroll was arrested Sunday in connection with a May 17 incident involving an 8-year-old girl. The girl told police she was at Carroll's house and that he asked her if she wanted to play a game. He then blindfolded her and assaulted her, police said.
News of his arrest and the videotapes investigators say they found shocked workers at the advocate program, said CASA director Laura Wolf.
"There's a deep sense of grief for the children and there is a deep sense of betrayal that we feel here," Wolf said. "Our first thoughts are with the children who have been victimized."
As a court-appointed advocate, Carroll's job would have been to get to know the abused child and their family, talk to their teachers, doctors and other and recommend a recovery plan to the court, Wolf said.
He also passed an extensive background check that included FBI fingerprinting as well as a check of state and national criminal databases. Personal recommendations from friends were glowing, Wolf said.
Carroll was being held at the Travis County Jail with bail set at $2 million.