After their family was shot at twice, Jeffrey and Yvonne Stern turned their home into a bunker.

"It's like Fort Knox here," said Yvonne Stern.

For two years, the Sterns, who have a million-dollar house near Houston, have been at the center of a headline-grabbing murder-for-hire case that has rocked Texas. Jeffrey Stern, a wealthy lawyer, will stand trial next week on charges of solicitation of capital murder. Prosecutors allege that Stern was behind a plot to kill his wife - an allegation Stern denies.

Yvonne Stern says she believes her husband was the victim of a fatal attraction and could not be responsible for trying to have her killed.

In an interview with "20/20? co-anchor Chris Cuomo, Yvonne Stern detailed the extreme measures her family took to try to stay safe while they remained perplexed by who could be behind the murderous plot.

Yvonne Stern shows Chris Cuomo the security features of her home. (ABC News)

On Feb. 12, 2010, the house was sprayed with bullets. The family dismissed the incident as random, but two months later, on April 15, a man wielding a gun rang the Sterns' doorbell. When Yvonne Stern opened the door, the man shot at her, missing her by inches.

That second incident just weeks after the first shooting convinced the family that someone was in fact trying to kill them, Yvonne Stern told "20/20."

The Sterns spent $75,000 to secure their house. They added a panic room, bulletproof glass, spotlights around the perimeter of their home and infrared cameras.

PHOTOS: Hit Men Tried to Kill Texas Wife Three Times

"Lots of cameras, at every angle,  for protection," Yvonne Stern said.

At Yvonne Stern's insistence, Jeff Stern bought a gun and the family hired a former Navy SEAL to teach them escape maneuvers.

While the house was being fortified, Yvonne Stern and the couple's two children moved into an apartment. But the mysterious threat the Sterns feared still caught up with them: On May 5, Yvonne Stern was in her Cadillac Escalade when a gunman shot through her car window. The bullet shattered the window and passed through her stomach.

Later, it was revealed that the man who shot Yvonne Stern - and the men responsible for the other failed murder attempts at her home - were all hired by someone close to Jeffrey Stern: his mistress, Michelle Gaiser.

Gaiser agreed to plead guilty to solicitation of capital murder last year for trying to have Yvonne Stern killed. In return for her plea and testimony, her potential life sentence was reduced to a maximum of 25 years in prison. She is scheduled to testify against Jeff Stern at his trial, which begins April 9.

Watch the full story on "20/20? Friday at 10 p.m. ET.