CHICAGO (CBS) — A security camera detected something moving in her backyard.

And when she checked the video, a north suburban woman saw a cat so big, she thought it was a cougar.

CBS 2’s Vince Gerasole has more with a story you’ll see Only On 2.

It’s not the environment you’d typically expect to find a cougar on the prowl.  But sightings in the area though rare but not unheard. Authorities are trying to determine just exactly what was roaming about a fenced in backyard.

On a sleepy suburban street, a security camera facing out the back door picked up the shadow of something out of the ordinary. The image is kind of over exposed but it sure looks feline, and appears to be big.

CBS 2 spoke with Marilynn Sullivan at the very spot of the sighting, her back porch in Gurnee.

“I looked at it and saw what I thought was a large cougar,” Sullivan said. “I looked at the picture and freaked out.” I’ve seen coyotes but they have long noses and this has a big cat face.”

Sullivan also found blood on her fence and something more: footprints. There were at least six footprints not far from the fence.  Sullivan’s two dogs have noticed something’s up too,

“They just go crazy barking,” Sullivan said. “Not someone at the front door barking, but angry, scared.”

Wild cat sightings are not new to metro Chicago. In 2008, a cougar even charged at a Chicago police officer. The animal was shot and killed in a Roscoe Village alley.

A trapper consulting with the state and now working with Sullivan is installing better surveillance cameras.  The nearby Des Plaines River has been a natural path for wild cats to occasionally follow.

But there is also the possibility that the frightening image was also an optical illusion and may have been a neighborhood cat perched on a nearby chair.

Sullivan doubts that’s the case.

“I have never seen a house cat that big but I don’t know. My only thing was make sure the neighbors safe,” she said.

Sullivan said her motion detectors have been picking up strange movement every morning about the same time for a few days now.

The Gurnee Police Department did not respond to requests for comment. A wildlife expert said with more people staying at home and with fewer cars on the road, wild animals like coyotes and raccoons have been reportedly venturing into areas that are usually more populated, like streets and yards.