The Official Account
Having denied for years that WTC 7 came down at free fall acceleration, NIST repeated this position in August 2008, when it issued a report  on WTC 7 in the form of a Draft for Public Comment.
Shyam Sunder, the head of NIST’s WTC project, said — speaking within the framework of its claim that the building was brought down by fire — that free fall would have been physically impossible. 
The Best Evidence
Scientific analysis  by mathematician David Chandler shows that WTC 7 came down in absolute free fall for a period of about 2.25 seconds. NIST’s Draft for Public Comment had been challenged by Chandler and Dr. Steven Jones in a public review, and NIST then re-analyzed the fall of WTC 7.
In its Final Report,  NIST provided a detailed analysis and graph that conceded that WTC 7 came down at free-fall acceleration for over 100 feet, or about 2.25 seconds, consistent with the findings of Chandler and Jones.
References for WTC 7 Point 2
- NIST NCSTAR 1-9, Structural Fire Response and Probable Collapse Sequence of World Trade Center Building 7. Draft for Public Comment. August 2008.
- “ … you had a sequence of structural failures that had to take place. Everything was not instantaneous” (“WTC 7 Technical Briefing,” NIST, August 26, 2008). Although NIST originally had a video and a transcript of this briefing at its Internet website, it removed both of them. However, the video is now available elsewhere. Also available is its transcript, under the title “NIST Technical Briefing on Its Final Draft Report on WTC 7 for Public Comment.”
- David Chandler, “WTC7: NIST Finally Admits Freefall (Part I),” December 7, 2008, at 9:07. Chandler’s report of free fall was supported by NIST itself: NIST NCSTAR 1A, Final Report on the Collapse of World Trade Center Building 7, November 2008, p. 45f (pdf: 87f).
- NIST NCSTAR 1A, Final Report on the Collapse of World Trade Center Building 7, November 2008, p. 45f (pdf: 87f).