This photo doesn't show a section of Lanza's body !

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People seem to confuse that black mass near the gun as a body section of Lanza.
It is much more likely to be the bag of an investigator.
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This photo was probably taken before the other one because his Bushmaster XM15-E2S is still there and as you can see, that black mass is not there.
That means that it's unlikely that the black mass is a section of Lanza's body.
If anyone as more informations about these pictures, please write them in the comment section.

I am fairly sure that the confusion here is that the door that you are seeing in the second photograph is not the same door that is in the first photograph.

Based on a diagram of the room, the second photo appears to show the door to the restroom inside of the classroom, not the door to the hallway. If you look at this diagram, you can see that the Bushmaster was on the opposite side of the room from the Glock, which is on the floor just inside the doorway of the first picture. Adam's body was off to the side of the doorway, very close to the gun that he used to killed himself, so it would match up with the first photograph. (The left side of this diagram depicts the front of the school and the exterior windows through which the photo of the rifle was taken and the right side, "RM 10," shows the door to the hallway, as well as the door to the restroom in the lower right corner.)
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Here are two more photos taken from outside of the classroom windows. You can see the Glock on the floor here too and possibly the outline of Adam's legs/knees again. This door is very clearly the hallway door because you can see the hall and an open door into another classroom.
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This photo may provide a further reference point. If you look at the exterior windows, you can see that the paper candles that are hanging in the windows are only located toward the left side of the classroom and the windows near the right of the classroom (where the restroom would be located) are bare. This would sync up with the fact that the photo showing the rifle does not appear to have any decorations in the window but the photos that show the pistol are obscured by the decorations (and the first photo that you posted, which is taken from the hallway, shows the decorations as well). Room 10 is on the left of the photo and Room 12 would be further right, with the dividing wall being where the flag is located.
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sscc wrote:

I am fairly sure that the confusion here is that the door that you are seeing in the second photograph is not the same door that is in the first photograph.

Based on a diagram of the room, the second photo appears to show the door to the restroom inside of the classroom, not the door to the hallway. If you look at this diagram, you can see that the Bushmaster was on the opposite side of the room from the Glock, which is on the floor just inside the doorway of the first picture. Adam's body was off to the side of the doorway, very close to the gun that he used to killed himself, so it would match up with the first photograph. (The left side of this diagram depicts the front of the school and the exterior windows through which the photo of the rifle was taken and the right side, "RM 10," shows the door to the hallway, as well as the door to the restroom in the lower right corner.)
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Here are two more photos taken from outside of the classroom windows. You can see the Glock on the floor here too and possibly the outline of Adam's legs/knees again. This door is very clearly the hallway door because you can see the hall and an open door into another classroom.
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This photo may provide a further reference point. If you look at the exterior windows, you can see that the paper candles that are hanging in the windows are only located toward the left side of the classroom and the windows near the right of the classroom (where the restroom would be located) are bare. This would sync up with the fact that the photo showing the rifle does not appear to have any decorations in the window but the photos that show the pistol are obscured by the decorations (and the first photo that you posted, which is taken from the hallway, shows the decorations as well). Room 10 is on the left of the photo and Room 12 would be further right, with the dividing wall being where the flag is located.
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Thank you for the informations, I'm dumb.
Where did you find the first picture (The "drawing") ?

CALU wrote:

Thank you for the informations, I'm dumb.
Where did you find the first picture (The "drawing") ?

No problem. You're not dumb. It took me a moment to figure it out and you didn't even have the diagram in front of you. At first I was going to suggest that it was the door to room 12 but that wouldn't have made any sense because the door appears to be directly across from the window.

I believe that the diagram is located somewhere in the CSP documents but I don't know which file it's in so I referred to this blog.
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The first two pictures that I posted are from this page as well.