Beloit police are cracking down on registered sex offenders.... Investigators are looking for these men. Troy Darwin and Fernando Blanco-Melchor... Darwin's wanted for a sex offender registry violation... He's 27-years old... 5-feet 8-inches tall... 230-pounds with brown eyes and brown hair. Blanco-Melchor is wanted for 2nd degree sexual assault of a child.... He's 23-years old 5-one... 140-pounds with black hair and brown eyes. If you have any information about these two call Beloit area Crimestoppers.... And remember you don't have to leave your name and you could earn up to a thousand dollars.