MARTINEZ, Ga. (AP) _ In a boxy little house on a trim suburban street, police believe mild- mannered engineer Richard Daniel Starrett, perhaps under the influence of porn-fueled fantasies, assaulted young women while his wife was away.

He has admitted, police say, to kidnapping and assaulting three girls, killing one of them, and assaulting four others in Georgia and South Carolina.

Police in five other states want to talk to him.

When police earlier this month searched Starrett’s rented storage unit, a mile from his house, they found 935 pornographic books and magazines depicting sexual bondage, horror scenes and nudity. They also found criminology textbooks and books about serial killer Ted Bundy, who preyed on attractive young women.

And police said they found about 100 videotapes, some of which were of Starrett’s sexual assaults.

″He was, to his neighbors, a quiet, reserved, working businessman, a family man,″ says Columbia County Sheriff Otis Hensley. ″And there were no suspicions by any (fellow) employees, or not even suspicion by his family.″

Starrett, 29, a design engineer, came to authorities’ attention Feb. 10, when a 17-year-old girl, who vanished four days earlier from her Lexington County, S.C., home, ran to a house on Starrett’s street.

She told the occupants she had been imprisoned in Starrett’s home for four days - often in handcuffs - and that she had been sexually assaulted.

Three days later, police near Houston found Starrett asleep behind the wheel of his flashy red Camaro.

Now, he’s charged with kidnapping the 17-year-old, a 12-year-old and 15- year-old Jean Taylor McCrea, all of whom vanished from Lexington County, about 50 miles north of Martinez on Interstate 20.

The 17-year-old and the 12-year-old survived; the youngest girl was returned to her home shortly after she disappeared last June. Starrett faces false imprisonment, sodomy and child molestation charges in those cases.

Miss McCrea, who disappeared in December, was shot to death. Police say Starrett led them to her body, and they plan to charge him with murder.

Starrett also has admitted attacks on two women near Atlanta, one near Columbia, S.C., and one near Charleston, S.C., Hensley said.

Charges against him are pending in all three locations.

Police say they still don’t know why he did it, why he’s decided to talk about it or what other crimes he might have committed.

″This was just one of those situations where law enforcement did not have the clairvoyance to know something that even his own family members were unaware of,″ Hensley said.

Police say Starrett, who worked at the Savannah River nuclear power plant just across the border in South Carolina, was careful to keep his two lives separate, with his dark side hidden from his wife, Michelle. The crimes apparently occurred while she was making regular visits to California, police said.

Soon after the 17-year-old’s escape, a bizarre picture began to emerge.

Hensley says Starrett apparently chose at least some of his victims by going to the homes of people who had placed classified ads in newspapers, trying to sell merchandise. He abducted girls he found home alone, police said. The 17-year-old’s family, for example, was trying to sell a water bed.

The want-ad connection ″is pretty much similar in all the cases we looked at,″ says Hensley.

Within days, police in North Carolina, California, Texas, Alabama and Tennessee were considering Starrett as a possible suspect in unsolved abductions or sexual assaults in their states.

One of the managers at the storage warehouse complex where Starrett rented a unit said she was surprised by Starrett’s arrest and that it seemed uncharacteristic.

″He was more or less quiet. He never said too much when he came in,″ said Paula Snellings, co-manager of the Van Guard warehouse.

″I never would have imagined he would do something like that,″ she said. ″He was just too straight acting. He dressed neat, he drove a pretty car.″