A Scottish university lecturer faces a 15-year jail sentence after an FBI sting operation caught him travelling to America to have sex with a boy he met over the Internet. Dr David Steinheimer, 38, used sexually explicit emails and pornographic images of himself to "groom" a 13-year-old boy into meeting him for the purposes of having sex. Steinheimer had responded to an Internet advertisement placed by the FBI asking for pen-pals for a 13-year-old boy in Texas. The "boy" turned out to be an undercover FBI agent, who arrested Steinheimer when he flew to the US. The Net predator pleaded guilty to six separate charges on Sunday night, including using the Internet to entice an individual under 18 into sexual activity. He is currently being held in Texas federal prison, awaiting a prison sentence next month of up to 15 years and a £175,000 fine. The US prosecutor handling the case has warned that the history academic may have abused children in Scotland. "The fact that Steinheimer travelled from Scotland to meet a boy in the US would suggest to me that this was not his first time", said assistant US attorney Daniel C Rodriguez. The Aberdeen police force confirmed there are no current plans to launch a formal investigation into the matter. "We would have to establish sufficient grounds to merit an investigation into this area -- we have not yet received any complaints about the man," said detective inspector Thorburn at Aberdeen's Community Protection and Investigations Unit. In America, federal law enables FBI agents to enter chatrooms posing as children in order to identify and arrest paedophiles before any physical assault has taken place. Officers must, however, prove the suspect initiated the encounter, to prevent police from effectively framing an innocent bystander. In the UK, the Police and Criminal Evidence Act prevents sting operations, stating that such methods make police "agents provocateurs" and evidence gathered in this way is inadmissible. In the Steinheimer case, a specially-trained female FBI agent posed as a boy during taped telephone calls. The agency also gathered emails from the defendant to the boy that contained child pornography and sexual images of himself. Steinheimer had arranged to meet the victim outside an electrical store in a Houston shopping mall. At the hearing, Rodriguez rated Net paedophiles as a greater threat than traders in child pornography, as they seek to gain physical contact with children. Are your children in danger on the Internet? Find out with the Web of Porn Special Have your say instantly, and see what others have said. Click on the TalkBack button and go to the ZDNet News forum. Let the editors know what you think in the Mailroom. And read other letters.