MONROE — For months, Seattle police tracked the digital clues, seeking the man’s identity.

He sometimes went online to allegedly share explicit photographs of young girls. According to court papers, he reportedly sent emails about an interest in pedophilia, and a desire to wed a child as young as six.

In his various online accounts, the man used a distinctive online identity, “Karney37,” a possible play on the word carney, short for carnival worker.

Last week, detectives tracked the man down at his job. He was working as a carnival employee in the children’s amusement attraction at the Evergreen State Fair in Monroe.

Dale Roy Fager, 38, was arrested Friday on an arrest warrant out of Indiana and for investigation of trafficking in child pornography.

He was being held at the Snohomish County Jail in Everett on Tuesday in lieu of $250,000 bail.

There’s no evidence of any wrongdoing by the man at the county-owned fairgrounds, interim county spokeswoman Bronlea Mishler said Tuesday.

The arrest marked the second time in two years a suspected sex offender has been caught working at the fair.

In 2012, a young woman working at “Kiddie Land” was arrested because she had a court order to stay away from children. The woman had shown up in child pornography being created by her then-boyfriend. She was sent to prison last week in connection with that case.

After the 2012 incident, county officials began requiring and paying for background checks for all fair employees, Mishler said.

The suspect in this case passed the background check because it didn’t show his warrant in Indiana, she said.

The man was using an alias, according to court papers.

“Safety is our top priority at the fair,” Mishler said. “We’re disappointed that this happened, and we’re going to continue to be vigilant in the future making sure the people we have working in the fairground are quality folks.”

The investigation began in February when Microsoft alerted the National Center for Missing and Exploited Children that somebody using one of their digital services had uploaded at least one file of suspected child pornography.

A Seattle police detective sought search warrants for access to electronic records regarding the user. That reportedly led to Fager’s identity, in part because he was using the profile name karney37 on gmail and online dating sites.

Though he reportedly admitted writing emails that declared his interest in sex with children, Fager reportedly denied abusing anyone.

Fager reportedly said he is a drifter and “alone without any family because they have all disowned him,” court papers said. The company that hired Fager to work at the fairgrounds confirmed that he has been working at carnivals all over the West Coast.

Detectives said high bail is warranted.

“Fager has chosen an occupation as a carnival worker which puts him in direct contact with thousands of vulnerable children. This is a position of trust which allows for potential physical contact between Fager and unsuspecting children,” they wrote.

Seattle police said they’ve yet to complete a forensic examination of Fager’s phone. He told them that he used it and free wi-fi service to access the Internet.

Scott North: 425-339-3431, north@heraldnet.com