As devout Jehovah's Witnesses, they shared a devotion to God. The Murrieta, Calif., enclave they called home was rated among the safest neighborhoods in the nation.
Then, in April 2008, Isabelle was murdered at home -- and her husband was arrested and charged.
The police accused Kelle Jarka of having beaten Isabelle to death one morning and then staging a burglary to cover his crime.
They mustered an overwhelming catalogue of circumstantial evidence to incriminate him.
The police did not, however, have a clear motive -- or any physical evidence on Jarka.
Click HERE to watch Kelle Jarka's police interrogation.
Jarka had his own version of events, which he unfolded over a 10-hour interrogation with Police Det. Phil Gomez following the murder. On the morning Isabelle was killed, Jarka said, he got home, pulled into the garage and noticed signs of a break-in.
"The door inside of the house, I saw was open," Jarka tells Gomez on a tape of the interrogation session.
"Cracked open. And then, I saw the door that comes from the outside into the garage was open also."
In fact, the door to the garage appeared to have been forced open or kicked in. Wood fragments were found on the garage floor. And police found what they say was another key clue to contradict Jarka's story: On the fender of the car Jarka said he drove to the drug store and Starbucks was a small paint chip.
"Which would indicate that when that door was forced open," Gomez told "20/20." "The door jamb falls onto the car that's already parked there, Mr. Jarka's vehicle."
Gomez said that meant the car was in the garage, and Jarka was presumably home, when the forced entry was made.
For Part 1 of the Kelle Jarka story, click HERE.
The police were especially skeptical of what Jarka said he saw at the crime scene.
"I see everything's torn apart," Jarka says on the interrogation tape. "Drawers were pulled out. ... Her jewelry cabinet was off, thrown around. Other stuff all over."
That's not what investigator Danny Martin saw. He remembered "starting to think, hey look ... this looks staged."
"There were a great deal of drawers in the kitchen and the bedroom that had been taken out and actually removed from their track, and then neatly stacked on the floor, which I don't recall seeing at past burglaries," said Martin. "Typically in the cases that I've investigated, burglaries, the drawers aren't even removed. So it was odd that somebody took the time to actually remove these from their mechanism, place them neatly on the ground."
Police also found it strange that the "phantom burglar," as they called him, left behind $500 cash in a bedside table and two laptop computers, while taking a much heavier and more difficult to sell desktop computer tower.
All that evidence, however, paled in comparison to a discovery police made days after the murder. Prosecutors finally had what they say was a the clear motive for Isabelle Jarka's death.