In the "Secrets and Lies" Season 1 finale, Ben Crawford tries to enjoy the Christmas holiday festivities he had missed with his family, but the plans change when he makes a shocking discovery.

Meanwhile, the evidence collected from Tom Murphy's murder scene has been retested. Detective Cornell reviews all of the evidence and prepares to make an arrest. In the promo clip, she says, "I don't think Crawford killed anyone."

If Ben did not kill Tom, then who?

In another scene from the promo clip, Dave said, "Christy had the motive, and the opportunity."

In the clip's last scene, Ben is shown looking on in horror at a pair of scissors stuck into the wall near his head.

In the season's stunning conclusion, Ben will make a decision that will change his family's life forever.

Let's review the evidence along with Detective Cornell to solve this murder case.

In past episodes, Ben has flashed back to the night that Tom was killed. It was the same night that his wife, Christy Crawford, had confronted him about having an affair with Jess Murphy. Could Christy have killed Tom in a jealous rage?

But then Dave Lindsey made a shocking confession: On the night of Tom's death, he drugged Ben's drink at the bar to help him relax. It caused Ben to black out. The two men retraced their footsteps from the bar where Ben recalled waving an ultrasound photo of his unborn baby that night. Ben also found a child's tooth in his jacket pocket.

Against his lawyer's advice, Ben visited the police station and told Cornell about being drugged and the ultrasound photo. He also told her what happened when he arrived home that night: He got out of the taxi cab and saw Tom's tricycle sitting in the driveway at Jess' house. He moved the trike onto the lawn. He noticed that the television was on inside the house and went inside to switch it off. He wanted to warn Jess that Christy knew about their relationship, but Jess was asleep. Tom woke up to find Ben in the house. Ben took him back to bed where Tom's tooth had fallen out. Ben put the tooth under Tom's pillow for the Tooth Fairy. When Tom wasn't looking, Ben took the tooth and left money in its place.

Ben shared this information with Cornell because he knows that he did not kill Tom. Though Cornell could use this information against him, it now seems even she believes he is innocent.

The focus of Cornell's investigation will undoubtedly shift to Christy in the season finale.

In Episode 8 "The Son" of "Secrets and Lies," Ben's lawyer introduced an alternate theory, naming Christy as a possible suspect. The lawyer also noted that Christy had a large amount of money that Ben knew nothing about. Ben searched the entire house and found a safe loaded with tons of cash.

Could Christy have killed Tom after discovering her husband's affair with Jess? She would have had easy access to his flashlight. Share your theory and help solve the case in the comment section below.

Watch the "Secrets and Lies" finale, "The Lie," on Sunday, May 3, at 9 p.m. on ABC.