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