A couple suspected of stealing baby formula from a grocery store and leading police on a high-speed vehicle chase along Interstate 680 Wednesday morning were arrested after nearly crashing the car and being nabbed by a police dog, police said. Officers were patrolling the Bernal Safeway parking lot at 6790 Bernal Ave. when a man, later identified as Demarko Luke of Oakland, ran from the store carrying two baskets of Enfamil baby formula.