linked - Investigating the Terror

We conclude that Williams' VOD opinion lacked a sufficient scientific and
empirical foundation.
(a) Inconsistencies
At the outset we note that Williams has been inconsistent as to his
estimate of the VOD of the main charge at the World Trade Center. In his
report dated July 1, 1993, he stated that the explosive main charge was a
high explosive having a velocity of detonation (VOD) of approximately
14,000 feet per second. In his Salameh testimony in February 1994, he
gave a VOD of somewhere between 14,000 and about 15,500 feet per
second, with a little bit of give on each side of that. Later, in the Rahman
trial in April 1995, Williams testified:
From this walk-around [at the scene of the bombing] I was able
to look at the damage and conclude that I was looking at the
damage from a[n] explosive that had a velocity of detonation
around 14,000 feet per second.
Obviously, without being in there when the bomb went off or
seeing what kind of explosive it was, I have to give a bracket on
both sides of a couple thousand feet.
In his OIG interviews in February and March 1996 he also stated that his
VOD estimate included a 2000 feet per second tolerance on either side of
the 14,000-feet-per-second estimate--i.e., a range of 12,000 to 16,000 feet
per second. Finally, in a letter to the OIG in August 1996, Williams stated:
The other reason that I testified as to the VOD damage in the Trade
Center, is that from the damage I witnessed, it appeared to me that the
improvised explosive device was faster tha[n] 11,000 and slower than
16,000.
Thus, Williams has given four estimates of the VOD for the main charge:
approximately 14,000 feet per second (his report), 14,000 to about 15,500
feet per second with a little give on each side of that (Salameh trial),
around 14,000 feet per second with a bracket on both sides of a couple