BOSTON -- A Virginia man was arrested Friday at a Massachusetts train station on charges of child endangerment and attempted kidnapping.

Daniel O’Brien, 32, of Richmond, Va., took a Greyhound bus and a train to Littleton to see a 12-year-old girl with whom he had been corresponding, Middlesex District Attorney Gerry Leone said. The two had made initial contact over the Internet in a chat room, according to police.

O'Brien was arraigned Monday in Ayer District Court on charges of attempted kidnapping and child endangerment and ordered held on $50,000 bail.

Prosecutors said the girl had packed a bag and money and planned to "run away" with O'Brien.

Prosecutors alleged that O'Brien told police he planned to bring her back to Virginia and have her pose nude on the Internet. He also said he planned to marry and have babies with her, prosecutors said.

"This is a stark reminder of the type of predatory behavior aimed at vulnerable children that can occur on the Internet," Leone said. "Thankfully, the defendant was arrested before he was able to kidnap the victim and carry out his prurient intentions."

"The favorable ending to this potentially tragic case is due in large part to the alert reaction of the victim’s parents," Littleton Police Chief John Kelly said. “They were keyed into their daughter’s behavior, realized something was amiss and knew it was important to be intrusive."

King said the girl's parents found e-mails outlining the arrangement for the planned meeting.

Once in custody, police said O'Brien admitted that he knew the girl's age and that he intended to sexually assault the victim and place pictures of her in states of nudity on the Internet.

Prosecutors said O'Brien was corresponding with a few other people online, who also wanted his help to run away.

O'Brien is scheduled to return to court on Dec. 9 for a pre-trial hearing.