VIDEO: Mountain lion caught entering Brentwood homeowner's backyard

BRENTWOOD, Calif. (KGO) -- A warning from Brentwood police to be on the lookout for a mountain lion. One was spotted in a residential neighborhood near Fairview Avenue and San Jose Drive Tuesday morning.

Look closely here at the video above from Brentwood. That's not a dog, not a house cat, but it is a mountain lion.

"The camera caught it here but when I peaked out, it just scurried up so it basically just jumped from the ground straight up. Caught it's front legs up and then scurried, it was gone in like two seconds!" said Steven Fitzpatrick.

We spoke with Steven Fitzpatrick who spotted the lion in his yard just after 7 a.m. Tuesday. His backyard camera actually alerted him to it.

"Usually if it is a cat, it will say motion detected, but it said person was detected," he said.

There was no person, but there was a mountain lion. For a lion sighting in a residential Brentwood neighborhood, that might sound extremely rare but we talked with those from the California Department of Fish and Wildlife who said, not necessarily.

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"It's a little unusual but it does happen," said Steve Gonzalez with the California Department of Fish and Wildlife. "What most likely happened in this case. It's probably a young mountain lion looking for territory, stumbled into an area that it didn't belong, and is looking for a way back home."

"It was probably like 4 feet or so. That's why I know it wasn't as big as a normal mountain lion because a normal mountain lion would be bigger, but I could see it's ribs, so I couldn't tell if it was a cub or just malnourished," said Fitzpatrick.

"Mountain lion needs 200 square miles of territory. And so I always tell people, you go 200 square miles in California. You're gonna run into a couple of cities, towns, houses, and homes," said Gonzalez.

Gonzalez says mountain lions often come out at dusk and dawn. If you do come across one...

"Back away slowly, but look big. Put your hands in the air, wave, make noise, try and scare it away," Gonzalez said.