Transcript for Valentine's Day Murder: Former Baptist Missionary Accused in Wife's Death
And now to the trial of a former Baptist missionary, charged with killing his wife on Valentine's day. They say he wanted to be with a student coming to the U.S., he claims his wife was killed in a home invasion. Reporter: This morning, Nathan is on trial for first degree murder, accused of kills hi wife on Valentine's day last year. The 20-year-old Lithuanian sponsor student. Reporter: They claimed he killed her to be with the alleged mistress. I observed kitchen cabinets open and on the floor. I felt this was not a regular burglar. Reporter: He called police to say she had been shot in the head during a home invasion, but prosecutors say he staged it. It was a Glock 40, the same type of gun he owns, but reported stolen. S investigators also found his internet serchs for thousand muffle a gun, hitting someone to knock them out, and lethal injection. And read from the day planner. I know you want me dead, you want to humiliate me to run around with a 20-year-old. Reporter: She took the stand Wednesday, questioned about a text message she received 15 minutes after he called 911 to report his wife's murder. Do you recall texting back "Interesting" with a smiley face? Reporter: He has pleaded not guilty. There are certain pre-conceived notions of who did it, for the lack of a better term, that never went anywhere. Reporter: If convicted, he could spend up to 45 years behind bars. Reena ninan, New York. Now the check with ginger -- what's that bind you?
This transcript has been automatically generated and may not be 100% accurate.