Dateline | April 03, 2013
>>> when kevin mengel was a no show for the family barbecue on father's day, his sister michelle was disappointed and more than a little confused.
>> he had called my husband to say how excited he was to spend father's day that sunday with all of us.
>> reporter: so it was supposed to be a big father's day celebration.
>> big father's day, and he couldn't have been more excited.
>> reporter: kevin 's younger brother chris also knew how much he was looking forward to being with his family. after all, kevin had just reconciled with their dad after many rocky years.
>> i thought, man, this is odd. why would he do this now? it doesn't make any sense.
>> reporter: the story morgan , the wife, told was that kevin had taken off, told her that the marriage was over. in fact, by father's day, he'd already been gone for two days.
>> kevin 's fine, he's clearing his head.
>> reporter: what do you mean kevin 's fine?
>> he just had to leave and get away and clear his head.
>> reporter: she's trying to tell you he needed space.
>> he needed space.
>> i can see him blowing off and taking off and saying i'm just going to get away. so that part of me said okay. he just did that and he's going to come back in today or tomorrow.
>> reporter: we just have to be patient and wait?
>> yes, we just have to be patient.
>> reporter: patient because those close to kevin and morgan had seen the couples' ups and downs before. their breakups, in fact, were almost an annual event.
>> it was like clockwork, every august around their anniversary, we'd expect the phone call that morgan picked up and left. kevin would call us crying hiss ta tarikcally. he would be completely distraught.
>> he said, i love her. i can't help it. i love her.
>> reporter: and soon morgan would return. kevin 's world would right itself. and they'd be as good as newlyweds. for a while.
>> she could act like nothing ever happened. and acting all lovey-dovey, sitting down on his lap.
>> reporter: but now what was weird about this separation was that kevin had taken off. not the other way around.
>> she always took the kids, and she always left. kevin never once walked out on her.
>> reporter: his family worried this must have been the fight to end all fights. and it wasn't like kevin not to call his family for support. the only person he reached out to was his mom. a few days after he disappeared, he sent her a cryptic text message that seemed to alarm her more than put her at ease. and so kevin 's mom did something that seemed a little drastic. she called the west goshen police to report him missing.
>> we thought maybe she was overreacting to kevin leaving.
>> reporter: detective david maurer .
>> there was no reason to believe that anything had happened to kevin . she was receiving text messages from kevin 's phone.
>> their feelings were that if somebody's communicating with him, then he's not missing.
>> reporter: kevin 's dad agreed.
>> i was a little concerned that she may end up with a little egg on her face because he was going to show up and --
>> reporter: and she'd called the cops. okay. and not long after that initial missing person report was filed with the police department , an officer called the family back to say kevin had been spotted not far from his home.
>> one of the officers stopped at a check cashing place right up the street from where morgan and kevin lived. and the owner of the check cashing place was very familiar with kevin , and he saw him across the street. so that lended some credibility also that kevin was in the area.
>> reporter: he was close to home , sending texts to his wife and mother, just refusing to see or speak to his family. and he did finally respond via text to his father. what did you get back?
>> doing okay. just need time away.
>> reporter: and kevin 's sister received this message.
>> hey, sis, i'm fine. worry about morgan . she's the one you should be worried about.
>> reporter: but morgan , it appeared, was doing just fine. the couple owned a landscaping business. and monday morning morgan showed up to meet the crews and told them she was now in charge. employee al recalls she had the garage looking spotless.
>> there's always oil drips on the ground. this day, you could have ate off this floor.
>> reporter: but this was new, too, as al went about his monday landscaping jobs. he noticed morgan , the boss' wife, flirting with a 21-year-old employee named steve shappell.
>> morgan looks at me and says steve knows what color underwear i have. steve goes, yeah, pink with black stripes. right off the bat.
>> reporter: when al had a question about an assignment --
>> i would call morgan , and steve 's there. steve 's answering her phone.
>> reporter: why was this kid who mowed lawns and was barely old enough to buy a beer suddenly acting like the new man in charge? kevin 's sister michelle remembered him as a quiet unassuming young guy who'd done some work on her yard just weeks earlier.
>> this kid steve could not have been more polite to us.
>> reporter: so what would kevin think now of his employee spending the work day at the pool with his wife and kids as michelle observed when she took a drive by?
>> i drove by her development, and she was sitting out at the pool with steve and the kids.
>> reporter: okay, you see steve sitting with her and you think what?
>> i thought morgan was having another affair.
>> reporter: it was no secret among those that knew the couple that morgan had strayed before. could kevin had suspected morgan was at it again? and was that the final straw that drove him out? no way to know. he said was not taking calls. and then five days after he disappeared, kevin finally had something to say to everyone who knew him in the most public way possible. he posted an update on facebook . status -- wants to be left alone .
>> he wants to be left alone . some of his friends backed off then. his friends also were looking for kevin . after that facebook thing came up, they were like this must just be another morgan and kevin fight.
>> maybe he just kind of had a nervous breakdown or had enough, needed a vacation for himself.
>> reporter: but to kevin 's immediate family this facebook update was far from reassuring. to them, it was an ominous red flag .
>> every other update that kevin had put on there had come from his cell phone because it shows the little cell phone . this one came from a computer.
>> reporter: which seems so odd. the family knew that kevin did everything on his cell. what's more, the wording in the text messages he'd been sending just didn't sound like kevin . for example, michelle wondered when did he start calling her sis?
>> in the pit of my stomach, i just felt something bad had happened to kevin .
>> reporter: and if the cops would not investigate, the family decided it was time to do some detective work themselves.
>> i'm afraid his wife and the new boyfriend are making a move right now to leave. they're leaving.