The death of an endangered fin whale was a marine murder mystery. Now, we have a suspect: orcas.

• Orcas strike again!
• NOAA investigated the death of an endangered fin whale in California earlier this month.

An endangered fin whale died on a California beach this month — and the orcas would have gotten away with it too, if it wasn't for those meddling marine biologists.

The marine murder mystery was solved this week when the National Oceanic and Atmospheric Administration revealed the results of an investigation into the whale's death.

The whale had been found near Pacific Beach in San Diego on December 10 after it washed ashore. A crowd gathered and tried to help the creature, but it died on the sand, according to NBC San Diego.

There were no signs the whale had been hit by a ship, so its death was a mystery, NOAA public affairs officer Michael Milstein told Business Insider.

That is, until investigators discovered bite marks on the whale's fin.

"Fin whales are the second largest species of whale after blue whales, so it was a formidable target," Milstein said.

At first, it seemed like the zig-zag marks were from sharks, Milstein said. But investigators determined the wounds had a distinctive rake-like appearance, which points to one species: the orca.

"Killer whales are not all that common off Southern California but a group of about a dozen have been marauding along the coast, mainly preying on dolphins," Milstein said.

It seems the bite wounds weren't fatal, Milstein noted. Instead, the fin whale may have beached itself in a panic trying to avoid the predators, he said.

"It's interesting to see this kind of wildlife drama play out offshore of a big urban area such as Southern California," Milstein told BI. "The ocean may look calm but some wild things happen under the surface!"

In a way, the whale's death is a sign that conservation efforts are working, he added. The fin whale population has "rebounded" since it was driven to the brink of extinction by the whaling industry.

With the fin whale population recovering — as well as other marine wildlife flourishing — killer whales have a veritable feast available.

Orcas are intelligent apex predators of the ocean.

Orcas are among the ocean's most skilled hunters.

They normally scarf down on everything from walruses and seals to fish and sea turtles, but orcas have been known to go after bigger prey.

Recent research suggested orcas off the coast of Australia '"slurped" out the liver of a great white shark.

And near Portugal and Spain, orcas have been repeatedly ramming into boats, even sinking some.

But don't worry, those orca are almost certainly not looking for a human snack. Among the most likely explanations for the sudden surge in boat attacks: they're just playing around.