Los Angeles County prosecutors allege that a convicted sex offender tried to extort a teenager by demanding cash or sex for the return of her lost dog.

Deputy District Attorney Jan Perlstein says 27-year-old Alfredo Dempkey has been scheduled for arraignment Tuesday afternoon on a count of attempted extortion.

Prosecutors say the Lancaster resident found the dog Friday and used information on its tags to contact the owner.

A meeting was arranged at a fast-food restaurant, where Dempkey was arrested. The dog was returned to its owner.

Prosecutors plan to ask that bail for Dempkey be set at $170,000. A telephone listing for Dempkey could not be immediately located.