Roseville police are investigating allegations by a teenage girl that a male high school classmate made a videotape of her performing a sex act and used it to blackmail her. The female student told a Roseville Area High School counselor two weeks ago that the older male student claimed that he videotaped her performing a sex act at his family's Roseville home in March 2005, according to a search warrant affidavit filed in Ramsey County District Court. Since then, the girl told police, the male student, who is now 16, has threatened to show the videotape to her friends and...