Security video released of Rivera and son renting boat

The Ventura County Sheriff's Office has released video of actress Naya Rivera and her son arriving at a Southern California lake where she is believed to have drowned.

On Thursday the search for the "Glee" star continued at Lake Piru, northwest of Los Angeles.

Ventura County Sheriff's Sgt. Kevin Donoghue said Thursday there was no sign Rivera ever left the waters of Lake Piru, where her four-year-old son was found alone on a boat they had rented a day earlier.

He said the search has shifted from an attempt to rescue Rivera to an attempt to recover the 33-year-old's body.

Donoghue says surveillance video shows mother and son leaving the dock together.

He said Rivera had experience taking boats on the lake.