Now, to a brazen crime with a surprising happy ending that reveals something you may not know about hospitals all across america. A woman dressed as a nurse, walked into a southern california maternity ward and tried to walk out with someone else's baby. But as lindsey davis reports, the snatching was foiled by a twist in hospital security. A kind of electronic shield to protect newborns. Reporter: Watch as this woman, dressed in hospital scrubs, casually saunters into this southern california hospital. Surveillance video capturing 48-year-old grisel ramirez on the move. She would then walk into the maternity ward posing as a nurse, walk into a room to tl a new mother to take a shower before a doctor comes in to examine her. When that victim turned her back, went to take a shower, the suspect placed the baby inside of the tote bag and tried to leave the emergency room floor. Reporter: Police say ramirez, prompted by marital problems would then allegedly try to kidnap the baby walking out of the ward with the purple tote bag. Someone tried to walk out with a baby in a bag. Do we know if it's her baby? No it's not her baby. Reporter: Ramirez walked right into a high-tech security web. Babies today are given a tiny bracelet worn around their wrist or ankle. It works like a homing device, keeping track of the baby's ever move. You can tell where the baby is at all times? It becomes self-contained. Here at inglewood hospital in new jersey, there multiple signals, if I try and p it off, if I pass through a certain parameter or get too close to the door, at alarm sounds. Reporter: Nurses are instantly notified. Electronic security locks engage everywhere. Most maternity wards across the country now have similar features. A high-tech security solution formed more than a decade ago after multiple abduction attempts. Ramirez never made it past the hospital door, caught in that web of security. Lindsey davis, abc news, inglewood, new jersey.