The mother of Marvin Norwood -- one of two suspects in the vicious beating of Bryan Stow -- is coming out in defense of her son ... telling TMZ, "I don’t think Marvin did it. I believe he is innocent."
Marvin's mom Diana Page tells us, "He’s a good son and not capable of this type of behavior. He was a good worker. He takes care of his family."
Diana adds, "He’s a good father, he’s compassionate, and he has a healthy relationship with Dorene" -- Marvin's girlfriend -- who was also arrested in connection with the brutal attack of Stow.
According to Diana, "[Marvin] and his father used to have opposing views regarding sports teams, and they used to tease each other, but it never, ever got heated."
Diana says she hasn’t heard from Marvin since the arrest on Thursday, but believes justice will prevail ... in his favor.