A man is behind bars on suspicion of assaulting his mother in Santa Rosa, then stealing her Jeep SUV. Jacob McKean-Marioni was arrested after leading police on a slow-speed chase for less than a mile on Monday night. An officer used a stun gun on him after he started walking up the stairway leading to an apartment after the chase ended. Police say, a short time earlier, the 31-year-old had forced his way into his mom’s bedroom with a hammer, stabbed her with the hammer’s claw, then took her cellphone and car keys. McKean-Marioni allegedly became agitated and hostile after his mother asked him to leave her home.