A dolphin that washed onto a California beach last week died from a gunshot wound, KNBC reported.

Marine Animal Rescue posted a $5,000 reward to its Facebook page on Friday after a necropsy confirmed the animal had been shot.

Peter Wallerstein, founder and president of the rescue group, received a call about the dolphin in the surf on the morning of Nov. 8, NBC News reported.

"It's just a vicious act of brutality," Wallerstein told NBC News on Friday.

"There is NO excuse for such brutality against these beautiful animals," according to a statement posted on the Marine Animal Rescue's Facebook page.