did he say he loved you? yes. reporter: but rachel was hedging her bets. she told seth she was also interested in a co-worker named brandon who just happened to call her during her tryst with seth in the park. he started getting really jealous. so on the 20th when you were communicating with brandon, he said what? just give me two more weeks. did you ask what he meant? yes, he just repeated the same statement. reporter: six days later, lisa was murdered in her own bed. and here we have a motive that we can understand love, the whole relationship with rachel was evidence that was like a countdown to lisa techel s death. reporter: but defense attorney steve gardner countered, arguing the motive of an affair falls flat without the essential element sex. seth techel was being accused of murdering his wife for an affair that he was hoping to someday have. you never had intercourse with him? no.
confidante of seth s. i expressed that he needed to either end his marriage or end it with rachel. and saying that he should end his marriage with lisa techel, did he make any comment concerning child support? he asked me if i wanted to pay his child support. reporter: then the witness recalled another remark seth made about lisa. he stated that it would be better off if she was in a car wreck and died. reporter: prosecutors hoped their third time would be the charm. but the new defense attorneys would come at them with everything they had. and that included explosive new evidence. this time it was about lisa. coming up you found out the story that there was this guy, co-worker? right. reporter: was there another man in lisa s life? why hide your skin if dupixent has your moderate-to-severe eczema,
seth. on 294th you asked him do you really want to be with me, and he respond, forever. right. yes. reporter: that s may 24th, two days before lisa s death. and in a followup text, rachel asks second if he told his wife he wanted a divorce yet. and he responded, well, we talked, i told her i wasn t happy. she got mad, then sad, then i slept on the couch. so hello, mrs. resuscitator ? the. correct. reporter: the firefighter often bragged about his lifesaving cpr heroics. he was mr. reus istator and you were going to be mrs. resuscitator? yeah. reporter: to drive home the contention that seth chose murder over divorce, prosecutors called a co-worker who d been a
the state. they just said we forgot to do it. reporter: but the centerpiece of the defense case against the cops was something else they didn t do. they d been so busy investigating seth, who d been behind bars since his arrest two years before, that they never really paid attention to lisa. the new defense team would change all that starting with her cell phone and the secrets it held. you found out the story told by the phone, that there was some guy, co-worker right. reporter: it was a bombshell. lisa was having an affair with a fellow jailer. her lover was a married man, a father of four. this is not making out in the back of the car. no. he thought he he could be the father of the child. he thought that. reporter: so they called lisa s lover, jason tennis, to the stand. and back in may of 2012, did you know a lisa techel? yes, i do. reporter: jason testified that the affair started before lisa married seth and ended just
tryst with seth in the park. he just started getting really jealous. and so on the 20th when he learned that you were communicating with brandon, he said what? just give me two more weeks. did you ask him what he meant just give me two more weeks? yes, and he just repeated the same statement. six days later, lisa was murdered in her own bed. and here we have a motive that we can understand. love. the whole relationship with rachel was evidence that was like a countdown to lisa techel s death. but defense attorney steve gardner countered, arguing the motive of an affair falls flat without the essential element sex. seth techel was being accused of murdering his wife for an affair that he was hopin to someday have. you never had intercourse with him. no. you ve never had oral sex with him. no. never had your clothes off. no. and you kissed a few times. yes. is that a fair assessment of the extent of your romantic relationship with mr. techel. yes.