A Treasure Coast animal activist was hauled off to jail, after he says he was just trying to help a dog.

Indian River County SPCA President Van Demars was in the parking lot of a Sebastian shopping center when he spotted a dog that had been left alone in intense heat.  The dog was tethered to an SUV and sitting on the asphalt in 90-something degree heat. 

Demars took some video, called authorities and unhooked the animal. 

When the dog's 83 year old owner came outside, he was upset that Demars didn't give him the dog right away. 

Demars faces petit theft charges. 

Video: WPTV