This will be a 2-part post. The 1st part will explain the process of piecing together the Henkel duct tape segments in the exact sequence that they came off of the roll. The goal is to determine if the sequence will provide insight into their use.
Special thanks to AZLawyer, Muzikman, JWG and Valhall as theyve entertained my requests for information along the way without much of an explanation why.
The Henkel duct tape discovered on Suburban Drive can be summarized to include the following:
- Q62 attached to the skull
- Q63 attached to the skull
- Q64 attached to the skull
- Q100 apart from the skull, but, in the vicinity of the letters of the Big Trouble
t-shirt
One additional piece of interest for this post was recovered from the Hopespring Dr. residence:
- Q66 covering the vent hold of a gas can
This particular Henkel duct tape product includes a logo and text marking, alternating to the left & right of center along the length of the non-adhesive side of the backing.
Henkel logo pattern courtesy of our own FairNBalanced:
Using the Henkel logo marking pattern I determined the sequence that the segments of tape came from the roll... much like putting together a jigsaw puzzle.
When placed in the proper order each tape segment MUST align with BOTH the tear position AND the logo marking of the roll. This alignment process can also suggest if tape segments are missing from within a series if suitable matches for each tear are not found.
From the manufacturers specs cited earlier in the thread I used a tape width of 1.88. With this measurement I maintained the aspect ratio of each tape segments image and scaled it to its actual size. Fortunately, most of the tape segment images are reasonably close to being flat and straight. FWIW, I checked the lengths of the scaled tape segments against the lengths in the forensics reports. All were reasonably close, with only the scaled Q62 image being slightly longer (9.3).
Using a flat image of Henkel tape provided by FairNBalanced, and the known 1.88 width, I determined the repeat distance of the logo marking and replicated the text and the relative positions of each of the logo elements. I combined these to create a virtual duct tape stencil that I then overlaid on each tape segment. FairNBalanceds image was remarkably close to the repeat pattern I was able to see in the actual Q-series tape segments.
The virtual duct tape stencil also made it easy to see where the logo marking had degraded or was difficult to view due to the reflection on the plastic sample bags in which they were placed. In all tape segments, however, there was at least one, and in some cases multiple, logo & print marking(s) with which the virtual stencil could be confirmed and aligned. :thumb:
How logo alignment is done:
- I assumed that the logo on the Henkel tap is right-side up when pulling the tape off the roll in front of you. IF the logo is, in fact, upside down it would simply reverse the sequence of the segments.
- I also assumed that the segments of duct tape were torn and applied one-at-a-time instead of all of the pieces being torn from the roll before any of them were applied.
Heres and example of lining up two tape segment to determine which is the better fit using the logo pattern. Note that end matches can be eliminated easily when the logo appears out of synch with the stencil (left to right) OR out of synch with the lengthwise position of the logo.
I repeated this alignment test for all of the tape segments to determine if and how they fit.
After applying all possible combinations, the following best describes the sequence of taping that occurred:
1) Q64 applied first
2) Q100 applied second but NOT over Q64
3) Q63 applied third over Q64 at an angle
4) Q62 applied last over Q63
Only one end of Q100 among all of all the tape segments was significantly deteriorated enough to make the matching questionable. Fortunately, since there were excellent matches with all of the other tears, and since we also know that Q63 was attached on top of Q64, (the piece that came before Q100) it is reasonable to conclude that Q100 was applied after Q64 and before Q63, but, wasnt sufficiently caught between them.
Q64 Matches Q100:
I used the same process on the piece of tape from the gas can, Q66, and determined that it was not a fit EITHER BEFORE Q64 or AFTER Q62. This doesnt mean that Q66 didnt come from the same roll or batch, only that it wasnt taken from the roll immediately before Q64 or immediately after Q62. It is worth noting that the gas can tape analysis is not as straight forward as those found with the remains due to one of the images I have being on a curved surface, and the other providing only a partial view of the tape.
Next...if you have the patience for it
... Part 2 will use the sequence of tape pieces and a few other observations about them to suggest how they were applied.
