Idaho detectives say they are piecing together a story of what happened inside the house where 4 students were slaughtered, and they say video could be key, and not just what the videos show ... but what they DON'T show.
Aaron Snell from the Idaho State Police tells TMZ, his department is combing through videos which he suggests could provide clues, but then goes on to say, "What we need people to recognize is that often times what's not in the video might help us just as much as what is."
He goes on to say, "We can really create that whole picture based on what is there, what isn't there and be able to follow that through."
Snell would not get specific, but it raises the question ... is there an absence of third parties coming in and out of the murder house? As you know, police say the 2 surviving roommates are not suspects.
Police are looking at video the night before the murders, the night of the killings and what followed.
Snell says their hunt for evidence has been "very successful" ... video tips have been pouring in.
As we reported ... the 4 University of Idaho students were stabbed to death as they "likely" slept inside an off-campus residence. The assailant or assailants were armed with a combat knife similar to the one used by Sylvester Stallone's "Rambo" character in the '80's film, "First Blood."
Police have not located the murder weapon or released a motive for the attack.