Has the profile of Cooper changed over time? How does law enforcement's early profile of Cooper compare with a present day profile?
The short answer is, "Yes." The profile of DB Cooper has changed over time. That said, there are fractions within the FBI that see DB Cooper in different ways, so their "profiles" are not in agreement. In fact, I don't know of any definitive "profile" that has been developed. But we have the following:
1. Early on, Himmelsbach acknowledged that Cooper had guts and had the upper-hand for using a bomb. He saw Coop as a smart guy, but still called him a sleazy, rotten crook, although he has never described WHY he saw Cooper in those ways.
2. Some commentators, such as Walter Cronkite, described DB Cooper as a "master criminal."
3. Many FBI agents thought DBC was a professional skydiver and felt he would be found in the annals of the US Parachutist Association. Earl Cossey dispelled them of that notion, and that might have been the starting point of the drift towards viewing DB Cooper as a bumbling fool who was just smart enough to get himself killed.
4. That was the prevailing view of Larry Carr in the 2008-2010 era. The jump was too tough, he posed, and DBC died. Cossey added all the necessary plausible technical aspects to support that narrative.
5. However, when Cossey's reputation started going down the toilet in 2011 when GG's SKYJACK came out and our follow-up investigation of Norman Hayden and the parachutes, the FBI backed away from the tumbling, bumbling frostbitten fool who cratered. Curtis Eng certainly never gave his perspective on who DB Cooper might be, and held his tongue until 2016 when he wrapped up the case with Frank Montoya, Jr., who is now a talking head for MSNBC, btw...
6. That said, LD Cooper was described as the "most promising suspect" in 2011 when Marla walked through the door with an FBI imprimatur stamped on her Uncle LD dossier. However, the term "most promising suspect" was uttered by Ayn Dietrich-Williams. That suggests that LD looked pretty good for DBC in internal discussion up on 3rd Ave in Seattle, but that moniker never got pushed publicly once Ayn spilled the beans to journalist Alex Hannaford in June, 2011. Simply, no one has ever said WHY LD Cooper was so promising. Hence, many of us figured something else was in the works beyond LD's capacities to steal an airplane.