A 12-year-old California boy was arrested Saturday and accused of stabbing his 8-year-old sister to death and lying to authorities about it, sparking a furious manhunt for an unidentified intruder authorities now say never existed.

The boy's name was not released, but police in Valley Springs said he's believed to have murdered his sister Leila Fowler on April 27, after their parents left to attend a little league game. Police did not speculate on a motive.

The boy called police to report his sister's injury, claiming that he'd seen a man ran out of their home and then found his sister dying on the floor.

That story led authorities on a furious manhunt, going door to door in the small town asking residents if they've seen anything unusual, inspecting backyard sheds and even dispatching divers. Police also took up posts at schools and bus stops following the murder as the hunt for a suspect progressed.

Authorities said that more than 2,000 man hours went into making the arrest.

This video is from Fox affiliate KTXL-TV, aired Sunday, May 12, 2013.