Balian noted that Monday was the 28th anniversary of the day Linda and John Sohus were reported missing.
"What do we do with a case 28 years old?" he said, acknowledging there are no eye witnesses or physical evidence in the case.
"Circumstantial evidence is just as powerful," Balian said as he detailed the pieces of his puzzle.
"Not only does he flee, he changes his identity and discontinues contacts with friends. Why? Because he's a murderer," the prosecutor said.
Eventually, Gerhartsreiter turned up on the East Coast using the name Clark Rockefeller and living well at the expense of his wealthy wife.
Gerhartsreiter was previously prosecuted for kidnapping his own daughter and is serving a prison sentence for that crime.
Defense lawyers have suggested that he lived a life of pretense, making up wild stories about royal lineage, but they say he never killed anyone.
"He lied at will and his life was based on that," Denner said. "He said he was a filmmaker and he could amend the script anytime he wanted."
Balian reminded jurors of testimony by former friends from San Marino. A woman remembered seeing dirt in his yard where a large hole had been dug. A forensic expert said traces of blood were found on the concrete floor beneath a rug in the guest cottage the defendant occupied. But it was never clear if the blood was human or animal and it was not linked to Gerhartsreiter.
The prosecutor also emphasized what was found in the backyard grave along with bones — plastic shopping bags from the University of Southern California and University of Wisconsin at Milwaukee, two colleges the defendant attended.
"The case is easy," said Balian. "The evidence is right in front of your eyes."
The only thing missing, he acknowledged is a motive. Why would the defendant kill John Sohus?
"The prosecution need not prove why," he said. "It's not part of our burden of proof. Nor do we need to prove the type of weapon used or where he was killed."
Superior Court Judge George Lomeli instructed jurors that if they cannot agree on the charge of first-degree murder, they have the option of considering second-degree murder, which does not require premeditation.
He told jurors to return Tuesday for Balian's rebuttal before the start of their deliberations.