But Albrecht Muth's lawyer said yesterday during opening statements that his client is innocent and that prosecutors have no evidence linking him to the death of the 91-year-old victim.
Charged with first-degree murder, Muth could face life in prison if convicted.
"Albrecht Muth didn't kill his wife. The government has their theory but that's all it is, a theory," attorney Craig Hickein said. "And they can't prove that he did it because he didn't."
The death brought an end to a marriage marred by Muth's angry outbursts, occasional acts of violence and side relationships he had with other men, prosecutor Glenn Kirschner said.
Muth pleaded guilty to assaulting Drath in 1992. She alleged in 2006 that he had attacked her during an argument, and a computer repairman recalled seeing him shove her and curse at her during a visit to their home months before the death, Kirschner told the jury.
The unusual relationship, the couple wed in 1990, united a socialite well-known in diplomatic and political circles with a fellow expatriate nearly half a century younger.
Muth latched onto Drath's social connections, inventing various personas for himself, including of false claims being a brigadier general in the Iraqi army. He was known to stroll the neighbourhood in a purchased military-style uniform.
Drath's daughter, Fran Drath, testified yesterday that Muth, curiously, was wearing an eye patch when she met him.
Those eccentricities continued even after Muth's arrest.
He also fought unsuccessfully to wear a military-style uniform to court and to subpoena former CIA director David Petraeus as a potential witness.
On the morning of August 12, 2011, Muth called police to report having found his wife dead in a third-floor bathroom of their home.
