How do captors control their victims?

LOS ANGELES (KABC) -- There have been several cases in recent years of girls abducted and held captive for years. How do their captors keep control over them? And what becomes of their lives once they finally get free?

Several of these kinds of stories have made national headlines in recent years. A local psychologist says it's not at all uncommon for victims to sometimes sympathize with the very person that tore them away from their families.

They were shocking tales of abduction and captivity... Jaycee Lee Dugard was only 11 when she was kidnapped at a bus stop in South Lake Tahoe in 1991. She was kept in a concealed area behind her captors' house in Northern California for 18 years before being rescued in 2009.

In 2002, Elizabeth Smart was abducted from her bedroom at her family home in Salt Lake City. The 14-year-old girl was found with her abductor nine months later, 18 miles from her home.

Then there were the three women help captive for years in a Cleveland basement before one escaped last year. Ariel Castro's youngest victim was only 14 when she was abducted. The three women told authorities they were chained up and beaten.

According to a local psychologist, being held against your will doesn't always mean being held behind lock and key.

"This is all about control for him, power and control and dominance," said Dr. Leslie Seppinni, a doctor of clinical psychology and a crisis-intervention specialist. She says victims, especially young victims, can sometimes can become attached to their captors, a phenomenon known as Stockholm Syndrome.

"Which is where the person empathizes with their captor and begins to sort of believe that they are part of that family," said Seppinni. "And whatever their captor says to do, they do because they believe that they're part of that group."

And she says often threats of violence are used to control victims.

"Typically the captor will say 'I'm going to kill your parents' or 'I'm going to kill your sister,' or 'I know what school your brother goes to, where your mom works,'" said Seppinni.

And speaking in reference to the case in Santa Ana, Seppinni says the victim's ability to reach out to her sister probably gave her strength and courage.

"That shows that she still has that bond with sister. I don't know if her sister is older or younger, but she certainly has that familiar bond where she trusts her sister enough to do what her sister asked her to do," said Seppinni.

Seppinni says it's very likely that the victim in the Orange County case will suffer from a form of post-traumatic stress disorder, and that she will need therapy and the support of her family in order to readjust to her new life.