REDDING, Calif. -

Closing arguments began Wednesday in the Mark Duenas murder retrial.

Mark is accused of stabbing to death his wife, Karen Duenas, last year.

Shasta County Deputy District Attorney, Stephanie Bridgett, made the case Mark had the motive, means, and the opportunity to kill his wife.

While defense attorney, Ron Powell, told the jury to look at the case like a puzzle.

From the get-go law enforcement singled out Mark, and put aside the pieces to the puzzle that didn't quite fit, said Powell.

For a second time Mark watched as attorneys argued his fate, family and friends behind him, supporting him.

At the start of her closing argument Bridgett said, "something bad would have to happen for us to be together."

Investigators claim that's what Mark Duenas said to Annette Green, a woman, Mark was having an out of state phone relationship with.

Bridgett spent the morning laying out some 10 days of testimony she presented.

It ranged from the blood found on Mark's clothing, to his lack of concern, even Mark's so called insensitivity when he described finding his wife to investigators.

When Mark heard that argument he shook his head.

Bridgett argued Mark had the means to commit murder with plenty of access to knives in his home.

She said he had the opportunity, his son was gone for the evening and he had a motive, a crumbling marriage and a relationship with another woman.

When it was defense attorney Ron Powell's turn, he talked about discrepancies in law enforcement's observations of the Duenas' home.

He talked about the murder weapon, the knife.

He said if it was the kitchen knife where are the extra experiments to find knicks or blood on it?

Powell also questioned why tracks around the couple's home weren't looked into.

He also presented evidence about the window to Karen's room.

The defense attorney showed a picture revealing smudge marks on the outside of the blinds that could've been from an attempted break-in.

On Thursday morning the defense will wrap-up their closing arguments and the prosecution will have a chance to rebuttal before the jury begins deliberation.

The body of Karen Duenas was discovered on May 5, 2012. The prosecution claims she was slain at the hands of her husband of nearly 33 years, Mark Duenas.

Detectives performed several sweeps of the neighborhood saying they were looking for evidence but came up empty.

Shortly after the murder Mark was named a person of interest but was not arrested until Oct. 5, 2012.