reporter: in addition, detective salm would routinely log in to check on the whereabouts of peter and paul s trucks. and on the morning of thanksgiving day, more than four months after the bombing, salm turned on his computer to find the gps tracker on paul moore s truck. it had gone dead. we had no signal whatsoever. and this is also the type of gps that you could call. you know, just like calling on a cell phone. and wake it up. because they go to sleep when they re not moving. and where are you? we couldn t get a response from it. reporter: the device may have just died or been found, so salm got into his car with his partner, drove to paul s house to see if the truck was there. we got to his house. i look in the kitchen window and he s staring at me. okay. reporter: hoping paul hadn t recognized him, detective salm hit the road. as we re leaving town i look in the rearview mirror and there he is following us in his truck. he pulls in behind us. i speed up. he speeds up.
the moore family, doubled as the farm office. there were printers and copiers, envelopes, expected to be there, too. as you went around and found those things what were you thinking? we really want that one really, really good piece of physical evidence. reporter: what you found so far wasn t it. no. reporter: okay. so specifically what did you find of probative value? i didn t find anything. we took his cell phones. there were two cell phones in the car. reporter: but basically nothing. no. reporter: detective ruiz was assigned to the dining room, which clearly doubled as an office. what did you see? i saw a lot of paperwork. there was lots of paperwork. files everywhere on the table. reporter: room was full of paper. yes. reporter: the sun was just
breaking over the horizon. long rays of morning light angled through the blinds. detective ruiz was poking through all those papers and office supplies. when a curious thing caught his eye. it was the way that almost horizontal beam of light glanced off a blank sheet of paper. i noticed that the white sheet of paper had several impressions on it. reporter: impressions? yes. reporter: you mean writing on it? yes. like when you draw something on a top sheet of paper and it goes through. reporter: to the next sheet down. yes. and that got my attention right away. i picked it up and it was one of those moments where i was like, hum. i turned it different angles. the paper bowed in half. it was one of those, i was got chills the back of my neck. hairs are standing up. i m like no way. this is not happening right now. one of the officers helping us looked at me. he goes what are you looking at? because it was just a blank sheet of paper. and i was like, you re not going to be
reporter: but basically nothing. no. reporter: detective ruiz was assigned to the dining room, which clearly doubled as an office. what did you see? i saw a lot of paperwork. there was lots of paperwork. files everywhere on the table. reporter: room was full of paper. yes. reporter: the sun was just breaking over the horizon. long rays of morning light angled through the blinds. detective ruiz was poking through all those papers and office supplies when a curious thing caught his eye. it was the way that almost horizontal beam of light glanced off a blank sheet of paper. i noticed that the white sheet of paper had several impressions on it. reporter: impressions? yes. reporter: you mean writing on it? yes. like when you draw something on a top sheet of paper and it goes through. reporter: to the next sheet down. yes. and that got my attention right away. i picked it up and it was one of those moments where i was like, hmm. i turned it different angles.
we really want that one really, really good piece of physical evidence. reporter: what you found so far wasn t it. no. reporter: okay. so specifically what did you find of probative value? i didn t find anything. we took his cell phones. there were two cell phones in the car. reporter: but basically nothing. no. reporter: detective ruiz was assigned to the dining room, which clearly doubled as an office. what did you see? i saw a lot of paperwork. there was lots of paperwork. files everywhere on the table. reporter: room was full of paper. yes. reporter: the sun was just breaking over the horizon. long rays of morning light angled through the blinds. detective ruiz was poking through all those papers and office supplies. when a curious thing caught his eye. it was the way that almost horizontal beam of light glanced off a blank sheet of paper. i noticed that the white sheet of paper had several impressions on it. reporter: impressions? yes. reporter: you