MANCHESTER, N.H. -- Investigators are quick to admit they got lucky in detecting school bus driver John Allen Wright's sex abuse of children. A woman visiting a friend near Wright's Milton home unwittingly latched onto his wireless Internet connection and found sexually graphic images of children.
But getting the evidence to convict him of abusing the disabled children he drove and taping the abuse on a hidden camera required nearly 100 hours of computer forensic examinations by New Hampshire's Internet Crimes Against Children unit.
The unit was one of 10 formed nationwide in 1998. There are now 61 ICAC units in the country, growing in number and force as Internet use expands and criminals and their computers grow more sophisticated.
"It's such a scourge," said U.S. Attorney John Kacavas, whose office prosecuted Wright. "We can do this work all day, every day, and we would never catch up with it."
The number of child pornography complaints the New Hampshire unit received in 2011 rose to 178 from 116 the year before. Arrests went from 20 to 30, according to a U.S. Department of Justice report. ICAC units nationwide received 31,630 cyber tips in 2011, up from 23,314 in 2010.
ICAC investigators analyzed thousands of images on Wright's computer to figure out that he used a hidden camera in a pair of sunglasses to record the abuse. Wright, 46, was convicted of sexual exploitation of children and possession of child pornography. He was sentenced this year to 160 years in prison.
"That was a huge amount of work," said Portsmouth police Sgt. Tom Grella, who commands the ICAC unit. "We had to show that there was some device that was recording the acts."
At the core of the New Hampshire unit are certified forensic computer analysts from police departments in Portsmouth, Rochester, Hinsdale, Concord, Hampton and Nashua. The unit also has agreements with 67 police departments and a host of federal agencies to share expertise.
Hooksett Det. Caitlin Rebe was working on a case involving sexually explicit images on a juvenile's cellphone when she made her first trip to ICAC's computer labs, located within the Immigration and Customs Enforcement space in a federal building in Manchester. Rebe wanted to see if computer analysts could trace who sent the images and determine if there were other victims.
ICAC computer examiner Rick Nelson, a Peterborough police sergeant, walked her through how to retrieve the device's memory and copy it to extract any evidence without destroying the original. Rebe was hooked.
"I knew they could do it," Rebe said. "I just didn't understand how it all worked. I think it's fascinating to get into them and see where everything is hidden."
The unit was based in Portsmouth until ICE officials last year offered to let the unit use its facility in exchange for assistance with federal cases. The pact allowed ICAC to centralize six satellite workstations and brought additional equipment to the lab spaces, Grella said. The unit is funded by a U.S. Department of Justice grant -- $265,000 this year.
The unit gets about 30 tips a month, most from the National Center for Missing and Exploited Children's tip line. Other referrals come from social networking websites and school resource officers, Grella said. His unit also will venture into Internet chat sites to monitor exchanges.
Portsmouth Det. Mike Leclair, a lead investigator at ICAC, said the unit is investigating 50 cases.
"It can take maybe 40 to 80 hours to look at one computer, and that's without anything being difficult," Leclair said. Operating systems typically reveal websites visited even when the suspect uses wiping software to try to eliminate all trace of illicit conduct, he said. Leclair said they executed one search warrant on a man who had used wiping software and sat by as Leclair logged onto his computer.
"In under five minutes, I pulled it all up and said, ‘Here it is. What do you have to say for yourself?' and his very first comment was, ‘I'm going to sue that company!"'
Investigators have to compartmentalize the emotional impact of dealing with images of sexually abused children, Leclair said.
"You have to detach yourself," he said. "Otherwise, you dwell on it, and it can eat you up."