Story highlights A tip leads federal authorities to arrest a California man suspected of child pornography

The girl in several videos is safe, but other possible victims are being sought

Danish officials found the videos online earlier this month and alerted U.S. authorities

A pretzel bag available only in the U.S. and Canada narrowed the search

In a fast-moving child abuse investigation that started two weeks ago in Denmark, U.S. officials this week arrested a suspect in northern California and are now trying to determine whether there are additional child victims.

Federal authorities Thursday said they had arrested David John Stevens, 58, of Salinas, and believe him to be the man in four videos allegedly depicting sexual assaults on a young girl.

The girl, officials said, has been identified and protected. But based on interviews with witnesses, authorities "believe there may be additional unidentified child victims," the Immigration and Customs Enforcement agency said.

It could not be determined Thursday whether Stevens had an attorney.

The investigation was unusually quick, beginning May 4 when Danish National Police discovered four videos that had been posted on the Internet the previous day. Three videos were date-stamped April 14, and the fourth was dated April 27. Investigators were concerned that given the timeliness of the videos, the abuse might be ongoing.

Danish authorities, believing that the videos were shot in the U.S., shared them with ICE's Cyber Crimes Center, Child Exploitation Unit.

ICE investigators observed a Frito-Lay Rold Gold bag for thin pretzels in the videos. By studying Frito-Lay websites, they learned that Rold Gold pretzels are packaged differently within the United States and Canada. ICE investigators believe the bag is exclusively distributed in the United States.

On Tuesday afternoon, ICE investigators asked the public for help and released several photos culled from the video. On Wednesday, someone called the tip line, leading to Stevens' arrest that evening, ICE said. Investigators seized evidence related to the case at the suspect's Salinas home, ICE said.

The agency is asking anyone with further information regarding Stevens to call ICE's tip line at 866-347-2423 or the Salinas Police Department's Investigations Division at 831-758-7226. The public may also contact the Salinas Police Department anonymously by calling 831-775-4222 or by contacting the We-Tip line at 800-78-CRIME.

"When the (Homeland Security Investigations) special agents investigating this case ran out of leads, we turned to the media and the general public for help," ICE Director John Morton said in a statement. "A day later, a tip from the public has led to the capture of an alleged predator and more importantly, the rescue of a child. I applaud our investigators, the media and the brave individual who provided critical information. Without the public's help we would not have solved this case."