George Finley, 55, made the request to Justice Lynda Templeton as she was about to sentence him to 10 months for two counts each of Internet luring and possession of child pornography, the London Free Press reported.
Finley asked for the extra three months and also requested that he be sent to the Ontario Correctional Institute in Brampton, northeast of Toronto, so that he could "get help quick," the report said.
The judge hesitated, and then granted his request.
"This is one for the books," she said.
Finley's first conviction on pedophilia charges was in 1998. He also was convicted in 2005 and arrested again in January 2007 for breaching a court order by having child pornographic stories and videos on his computer, the newspaper said.
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