. >> reporter: detective scott gordon of the fairhaven police department was assigned to the case. first impression was suicide by carbon monoxide. >> it was apparent that he placed a water pump in the rear of his truck. and eventually, he passed away as a result of the carbon monoxide from that. >> reporter: to those who knew conrad best, it didn't make sense. had they missed something? conrad had been getting help, taking medication, and seemed hopeful about his future. his grandmother remembered him using that very pump to help out his dad just days before. >> i can still see that smile on his face. this little smirky smile that he always had. >> reporter: and his father recalled the two of them working on a job together a week earlier, setting up fireworks on a barge. >> we were, like, laughing. we're watching fireworks. he seemed fine. like when i left, um, the last thing i said to him was, i love you. and he said "i love you" back. >> reporter: so his family wondered what pushed him over the edge. as they struggled with their grief, they got comfort from a surprising source,