Prosecutors have said the couple's account at Regions Bank in Selmer was overdrawn by nearly $5,000 and that bank employees called Mary Winkler several times in the days before Matthew Winkler was found shot to death in the church parsonage.
Diane Hollingsworth, a teller at Regions Bank, said she talked with Mary Winkler on March 21, 2006 - one day before her husband was found dead in this west Tennessee town.
"I just advised her that if she came in and talked to our bank manager that there would be some way that we could work it out - that it was not an impossible situation," Hollingsworth said. "I advised her if she wasn't able to come in, it would be turned over to our security department."
Prosecutors have said Mary Winkler was caught up in a swindle known as the "Nigerian scam," in which victims are promised riches if they advance money to cover processing expenses.
Defense attorneys have said the Winklers were both taken in by the scam.
Mary Winkler, 33, was arrested a day after the shooting on the Alabama coast, about 340 miles away, where she was spotted driving the family minivan with their three young daughters inside.
Investigators say she admitted shooting her husband and that it had something to do with his constant criticism.
Three bank tellers testified that Mary Winkler had a separate account at the First State Bank in Henderson, about 20 miles north of Selmer. They say she deposited through an automatic teller machine a number of large checks from her First State account into the Selmer bank - including one for $7,000 and two for $4,000.
"I called to explain to her that the items she had been depositing on the First State account, there were no funds there," Hollingsworth said. "That simply was not legal."
The tellers also said Mary Winkler deposited a $6,455 check, allegedly from a Canadian Trust Bank, in December 2005 that turned out to be fraudulent.
Also testifying on Saturday was Steve Scott, a firearms expert with the Tennessee Bureau of Investigation, who said he found that the shotgun from which the shot that killed Matthew Winkler was fired was properly working.
"I've found no dysfunction in the firearm that would cause it to fire other than by pulling the trigger or applying 3Â¾ pounds of pressure on the trigger," he told prosecutor Walt Freeland.
Defense attorney Steve Farese asked Scott if a person could accidentally cause the gun to discharge. When Scott said he'd never personally experienced such a situation, Farese questioned Scott about gun safety.
"People without working knowledge of guns is more dangerous," Scott said.
The defense team has said the gun may have accidentally discharged while Mary Winkler was holding it and standing on pillows that were on the floor of the couple's bedroom.
Defense attorneys also say Mary Winkler was abused by her husband, and that she was attempting to confront him about a situation involving their 1-year-old daughter, Breanna, just before his death. The defense has not described the situation.
McNairy County sheriff's deputies stepped up security Saturday afternoon at the courthouse, which was packed with spectators, after the court clerk received a call from a person who complained that prosecutors were not doing their job properly.
A handheld metal detector was used to search each member of the public who entered the tiny courtroom.
Judge Weber McCraw recessed the trial until Monday morning. Jurors for the trial, which may last another week, are sequestered and are staying in a small-town motel without television, radio or cell phones.