"In these situations where women are intimidated and controlled, they have sometime made peace with a kind of subservience. They go along with the program and lose track of their moral boundaries. They've defined what they're doing as keeping the guy happy and placated," he said.
Details of Nancy Garrido's alleged involvement in Dugard's 1991 abduction are still emerging, though it appears she may have played a role both in the kidnapping and her two-decade captivity in which Phillip Garrido raped her and fathered her two daughters, now 15 and 13 years old.
Phillip's brother, Ron Garrido, described Nancy as "a robot," in an interview with the San Francisco Chronicle.
Adding to speculation about the nature of the Garridos' relationship and Nancy's own judgment are the circumstances under which she met her husband..
The two met while he was serving time at the federal penitentiary in Leavenworth, Kan., for a 1976 rape.
A jury will ultimately have to decide whether Nancy is a battered woman or an accomplice, said Gloria Allred, a California defense attorney, not involved in the case.
"Her best defense is if she didn't actively participate in the abduction. The worst case is if she did participate. Were there threats made against her? Was she physically abused?" Allred said.
The battered-wife defense was successfully used by Hedda Nussbaum, a New York City book publisher who was accused of aiding her husband, Joel Steinberg, in the abuse and 1987 murder of Lisa Steinberg, the 6-year-old girl who lived with the couple as their daughter.
Nussbaum, who was severely abused herself, became a cause celebre of women's rights groups and was ultimately acquitted, though Steinberg was convicted.
In another case from the 1980s, Sunset Strip Killers Doug Clark and Carol M. Bundy were convicted of a series of sexual murders in Los Angeles. Their victims were young prostitutes and runaways.
In a particularly gruesome murder, Clark took the severed head of one of his victims and had oral sex with it in the shower and stored it in an icebox. Bundy, who died in 2003, admitted she had been present at some of the murders.
Clark remains on death row.