Video shows a couple and two kids crossing into Mexico around the same time the McStays' vehicle was towed away from where it was found parked near the San Ysidro border crossing.
Family members have seen the video and cannot confirm it is the McStays.
Joseph McStay and his wife, Summer, and their two sons, Gianni and Joseph, both 3, were last seen February 4.
Both McStays left behind their two dogs and their cell phones and Summer left her eyeglasses.
Anyone with information about the McStays is asked to call San Diego County Sheriff's Dept. at 858-565-5200.
