"Return to Sender" is the sixth episode of the first season of the American television drama series Dexter, which first aired on November 5, 2006, on Showtime in the United States.

Meanwhile, his girlfriend Rita Bennett (Julie Benz) tries to prevent her husband Paul from attending their daughter's birthday party, and Lt. María LaGuerta (Lauren Vélez) considers adopting a young witness of the murder whom she finds at the crime scene.

Though set in Miami, Florida, the episode was filmed at various locations in and around Los Angeles, California including a salvage yard, a field by Tujunga Wash and a waterfront house on Hibiscus Island.

Goldwyn, who Erik King said was "a joy to work with", allowed actor C. S. Lee to improvise and David Zayas to memorize his Spanish lines in English and translate them mentally during each take.

While eating breakfast with Rita, Dexter is called to a crime scene, only to discover that it is the salvage yard where he committed a double murder the previous night.

He finds Valerie Castillo's body lying in the Airstream trailer where he killed her and her husband Jorge, despite having thrown the corpses into the ocean.

Dexter realizes that this is a hint from the Ice Truck Killer, leading him to go to the salvage yard and plant Jorge's fingerprints and a knife bearing a dry drop of Valerie's blood for Doakes' men to find.

The day of filming in the salvage yard, which took place at LA Japanese Auto Parts in Sun Valley, California,[2] was abnormally hot according to Lauren Vélez.

[3] Other filming locations included a waterfront house on Hibiscus Island in Biscayne Bay, Florida as the Castillos' home,[4] an empty field next to Sun Valley's Tujunga Wash where a young Debra practices shooting with Harry's pistol,[5] and a house in a residential neighborhood of Long Beach, California which stands in for Dexter's childhood home.

[10] Both Malene Arpe of the Toronto Star and Daniel Fienberg of Zap2it were disappointed with the episode's audio commentary featuring Jennifer Carpenter, Erik King, Lauren Vélez and David Zayas on the first season DVD.