"He opened the can and he said there's a shark in there and figured it was some little tiny, small thing," said Mary Ridenour.
The sharks were taken to the Southeast Area Animal Control Authority in Downey, where veterinarians will determine how they died. Investigators say one of the sharks had a 3-inch incision on its belly that looks like it was made from some type of blade.
"This is probably one of the most usual to find two sharks inside of a trash can," said Sgt. Chuck Miller from the Southeast Area Animal Control Authority. "Sharks on the coastline is one thing but in a residential neighborhood inside a trash can, not the usual, not the norm."
Leopard sharks can grow to be 6 to 7 feet long. Both of the sharks found were more than 3 feet.
Authorities said it is illegal to keep leopard sharks under 36 inches and larger animals require a permit from the state Department of Fish and Game.
Baby leopard sharks are popular with aquarium hobbyists, but often grow too big for their tanks.
The Ridenours are wondering why they were picked at random.
"I just wondered who would have threw it in there, but I guess they wanted to get rid of it. I don't know," said Ridenour.
Anyone with information is urged to call the Southeast Area Animal Control Authority at (562) 803-3301.
The Associated Press contributed to this story.