The man suspected of being the East Coast Rapist made his first appearance in court on Monday.
"Why haven't you picked me up sooner?" Thomas reportedly said to arresting officers last week, according to the prosecutor at the hearing.
At a press conference in Prince William County, investigators said it was a tip from Prince George's County that led to the suspect's capture. Officers said an anonymous caller provided detailed information about the suspect to the Prince George's County Crime Solvers hotline. Original reports that said the tip came from Prince William County were wrong, investigators said.
Authorities suspect the East Coast Rapist in at least four sexual assaults in Prince George's County.
"We always expected that a tip would lead us to a successful conclusion to this case," said Fairfax County Police Chief Dave Rohrer.
Investigators said the case was so difficult because the incidents took place across such a wide geographical area. They said at one point, more 700 individuals were suspected as potential suspects in the case.
Authorities said they used a data sharing program called LINX to narrow down the suspects to a "short list." Aaron Thomas was part of this list.
In late February, billboards went up across seven states with the mug shot of the suspect and a website was launched with information on the crimes. Police chief Roar said that the website recorded 169,000 page views.
Virginia state prosecutors said Thomas faces five life sentences for crimes of rape in Virginia. Since he also faces charges in Connecticut, he may not be tried in Virginia until that trial concludes.
There is a five year gap in the East Coast Rapist's attacks, between 2001 and 2006. Police said that they are continuing to search for new evidence or victims in the case.
Ronald Hosko, an FBI special agent who had worked on the case, praised the cooperation of Virginia's law enforcement organizations on the case. "It was a good week for agencies involved," he said. "It was a week when the predator became the prey."
The suspect could have been caught years ago if police had been allowed to check for family members who matched the DNA profile that had been developed, authorities said. Most states don't allow the use of familial DNA searches because of privacy concerns.
In certain cases, police submit a DNA profile that does not contain an exact match but appears to indicate a family relationship with someone known to authorities. If police had been allowed to use such searches for the East Coast Rapist, authorities said they would have arrested Thomas years ago because he did have a family member in a police database.
The arrest of Thomas is a highlight in the career of Prince William County Commonwealth's Attorney Paul Ebert. He said that the public's concern over the rapist approached that of the D.C. sniper in 2002, who also targeted Prince William County.