Ten months ago, Scott Peterson was a husband and father-to-be, a ferilizer salesman, a member of the Modesot Rotary club and the Del Rio Country Club, a guy who fished and golfed.

Now he's none of the above.

Peterson, who turned 31 Friday, is among the best-known murder defendants in the country, thanks to relentless media and a compelling story. A former jail trusty said Peterson spends his days in a dank cell, watching TV, reading fan and hate mail, and sometimes playing chess with other inmates.

The transition has been well-documented and little-understood.

Most accounts portray Peterson's early life as unremarkable. Youngest of seven children. Star of the high school golf team. Charming and confident -- or arrogant and pompous, depending on who's doing the remembering.

Peterson briefly attended Arizona State University, returning when his parents moved from San Diego a few miles north to Solano Beach. Eventually he enrolled at California Polytechnic State University, San Luis Obispo, where he met Laci Rocha while waiting tables at a cafe.

They married and owned a sports bar and grill, The Shack. Eventually they sold it and moved to Modesto, closer to Laci's family.

Friends have said Scott Peterson appeared devoted to his pregnant wife and had made a room in their home a nursery. Witnesses said he was troubled and anxious when Laci disappeared on Christmas Eve.

Others questioned his cool demeanor in the ensuing weeks, as hundreds of volunteers searched for Laci and camera crews descended. He participated, but some observers said he seemed detached.

Scott Peterson, who had denied romantic involvement with other women, eventually admitted a romance with Fresno massage therapist Amber Frey.

He claimed he told his wife of his affair in December. He said, "It was not a positive, obviously. It's inappropriate, but it was not something that we weren't dealing with."

Partial phone records later revealed that he continued to talk with Frey regularly for four weeks after she went public.

Pundits increasingly had a field day with Scott Peterson's story and actions.

He said he went sturgeon fishing alone on San Francisco Bay on Christmas Eve, in a 14-foot boat. He sold Laci's Land Rover and bought a truck, and contacted a realty agent about selling the house -- all before her body was found near the spot where he said he fished.

He appeared frustrated when police searched his home, removing loads of items -- including guns, The Bee learned. When authorities arrested him April 18 near San Diego, his hair and new goatee were blondish-orange, and he had more than $10,000 in cash and his brother's identification.

Peterson has appeared much thinner at recent court appearances. Occasionally he turns to smile wearily at family members -- a very different man from the one the world discovered 10 months ago.