London, Aug 31 (ANI): Police suspect that 'American Fritzl' Phillip Garrido terrified Jaycee Lee Dugard by taking her to sites where he may have killed 10 prostitutes.

Garrido kept Jaycee as his sex slave for 18 years and fathered two children with her.

It is believed that his horror tour for the three was meant to make them too scared to flee him, reports the Daily Star.

And it left the mother and her two daughters suffering from Stockholm Syndrome where hostages grow emotionally attached to their kidnappers.

Detectives suspect that convicted rapist Garrido, 58, could be one of America's worst mass murderers.

It is being said that Garrido may be responsible for unsolved killings dating back to 1998.

The bodies of 15-year-old school- girl Lisa Norrell and three strangled and stabbed hookers were dumped on an industrial estate in the nearby town of Pittsburg where he worked at the time.

Call girls Valerie Schultz, 27, Rachael Cruise, 32, and Jessica Frederick, 24, were mutilated and left in ditches.

Seven other prostitutes also went missing but their bodies have never been found.

And police now know that Garrido took Jaycee and her daughters - named as Starlite and Angel - to the same town just a few weeks ago. (ANI)