A 23-year-old man from Little Canada accused of answering a Craigslist ad for a baby sitter and using the child to make a pornographic video pleaded guilty Wednesday in federal court in Minneapolis.

Aaron Jay Lemon remained free on bond after his plea before U.S. District Judge David Doty. A sentencing date has not been set.

Lemon was charged Aug. 5 in connection with the incident, which occurred in August 2007 in St. Paul. He was released in August on a $25,000 bond after he was charged, a spokesman for the U.S. attorney's office said.

He also initially was indicted by a grand jury on charges of possessing and distributing child pornography in December 2006 and June 2008.

Lemon could face a maximum of 30 years in prison.

A phone number listed for the apartment he shared with his mother in Little Canada has been disconnected.

Lemon's attorney, John Fossum of Northfield, Minn., did not return a phone call seeking comment.

The case was the result of an investigation by St. Paul police.

According to the Justice Department, one in 33 children receives an unwanted sexual solicitation online each year.

One in four children experiences unwanted exposure to sexually explicit material on the Internet each year, and more than 20,000 images of child pornography are posted on the Internet every week.

Moreover, recent research by the Federal Bureau of Prisons indicates a strong correlation between possessing or distributing child pornography and committing sexual crimes against children, a news release from the U.S. attorney's office said.

The incident involving Lemon also put another negative spotlight on Craigslist, a central network of online communities that features free classified advertising for everything from cars and real estate to jobs.

Katherine Ann Olson, 24, was killed in October 2007 after she answered a Craigslist ad for a baby sitter. Michael John Anderson, 20, of Savage, is scheduled to stand trial in her death sometime next year.

Two defendants pleaded guilty earlier this year in federal court in St. Paul to advertising for sex partners on Craigslist so they could pick the pockets of those who responded. Then they allegedly used stolen IDs, checks or bank records to buy merchandise and prescription painkillers.

The San Francisco-based Craigslist announced earlier this month that it has entered into a pact with more than 40 states and territories to prevent people from posting classified ads that can facilitate prostitution, human trafficking, child exploitation and other illegal activities.

Pat Pheifer • 651-298-1551