WASHINGTON (CN) – Six months ago, Thomas Colbert ended a seven-year private investigation of D.B. Cooper – the now infamous skyjacker who disappeared after parachuting out of a commercial airliner in 1971 with a $200,000 ransom.
Confident he has definitively unmasked Cooper’s true identity, Colbert now wants to explain how his team members decrypted hidden messages they believe the hijacker embedded in letters sent to several newspapers in the days, weeks and months following the hijacking.
There are six messages in all, and the FBI turned them over to Colbert’s team following successful litigation under the Freedom of Information Act.
Mark Zaid, a national-security attorney working on the investigation, said in an interview that they found the most damning piece of evidence in the sixth and final letter to come to light.
Mailed from Florida on March 28, 1972, the letter says the hijacker is alive and has just returned from a trip to the Bahamas.
“So your silly troopers up there can stop looking for me,” it states. “This is just how dumb this government is. I like your articles about me but you can stop them now. D.B. Cooper is not real.”
But a code breaker on Colbert and Zaid’s team said their decryption efforts on the sixth letter unearthed an embedded confession: “I’m LT Robert W. Rackstraw.”
“It specifically identifies by name the very person we have been stating all along is the true hijacker,” Zaid said in a phone interview. “And he remains alive and well in the San Diego area, and we’re all waiting for the FBI to make the next move.”
Rackstraw, a 74-year-old former U.S. paratrooper still living in southern California, refused to be interviewed for this article. The Vietnam War veteran has long denied in press reports, however, that he is the man who hijacked Northwest Orient Flight 305 on Nov. 24, 1971.
Last year, in a friend of the court brief he filed in Colbert’s FOIA case, Rackstraw accused the investigators of ruining his life.
The FBI did have Rackstraw on their radar in the early 1970s, but later cleared him. Colbert, a producer who wrote a book about Cooper called “The Last Master Outlaw,” believes this decision was negligent.
Secret Messages Decoded?
To decode the Cooper letters, Colbert recruited another Vietnam veteran named Rick Sherwood. During the war, Rackstraw briefly served as a chopper pilot in the same unit as Sherwood: the Army Security Agency’s signal-tracing chopper program called Project Left Bank.
That’s where Sherwood learned the alphabet-numeric coding, which he describes as two years of college jam-packed into 16 weeks of training. Rackstraw, whom he says he did not know personally, would have learned it there, too, and Sherwood believes he used it to encrypt messages in the six letters.
The code transforms letters into numbers and vice versa, where A=1 and B=2, etc. So the word sun, for example, would equal 54 when the numeric values for each individual letter of the word are added up (S=19; U=21; N=14).
But Sherwood says anyone trying to decode an encrypted message would need to know something about the person who wrote it.
Having familiarized himself with Colbert’s work prior to joining the team, Sherwood had Rackstraw in mind while analyzing the letters. But he also looked for clues in the letters that would point him to where the secret messages were located.
In the sixth Cooper letter, Sherwood says he noticed that the author repeated certain phrases or words.
“And please tell the lackey cops D.B. Cooper is not my real name,” the letter says. The author used the word lackey more than once, and also twice denied that D.B. Cooper is real.
If D.B. Cooper is not his real name, then Sherwood wondered what was.
Over several weeks he says he tried to answer that question by zeroing in on the following phrase: “and please tell the lackey cops.”
When he added up the numerical value of those letters, he came up with 269
(And=19; Please=58; Tell=49; The=33; Lackey=57; and Cops=53).
He then wrote out a list of ways that Rackstraw could identify himself and determined that the phrase “I am 1st LT Robert Rackstraw” equaled 269.
These words actually add up to 287 — a fact that when brought to Sherwood’s attention led him to disclose that he had miscalculated the numeric value of Robert as 60, rather than 78.
It took Sherwood some two weeks to decode the sixth D.B. Cooper letter. In describing his decoding process, Sherwood said he worked on breaking the codes by making lists of possible phrases, working up to 10 hours a day.
After going back over one of those lists on Monday, he found a phrase that does add up to 269: “I’m LT Robert W. Rackstraw.”
Colbert said in a phone interview Monday afternoon after Courthouse News found the error that the decoding methodology leaves some wiggle room for small errors.
“There could be one or two words that are different as long as the theme and the message of the sentence is accurate,” he said.
Following up in an email sent Monday, Colbert said the buck stops with him, not with Sherwood.
“In our excitement last May at discovering this unexpected note, he was sloppy and I forgot to double-check him,” Colbert said.
But that wasn’t the only error Courthouse News found.
Sherwood had decoded another part of the sixth D.B. Cooper letter.
“I want out of the system and saw a way through good ole Unk,” the letter states, apparently referencing Uncle Sam. The author of the letter had used the phrase Uncle Sam more than once, as well as system, which Sherwood said drew his attention.
Focusing on the latter part of the sentence, “through good ole Unk,” Sherwood added it up to equal 216.
In trying to answer the question of how D.B. Cooper got out of the system, he tried out the phrase “by skyjacking a jet plane.” Sherwood miscalculated the numeric value of jet, however, wrongly concluding that the letters in the phrase added up to 216.
When Courthouse News checked the math, it added up to 221. After rechecking his work Monday, Sherwood came up with another phrase that does equal 216: by hijacking one jet plane.
Sherwood’s Prior Work Is Accurate
Sherwood acknowledges that the methodology isn’t perfect, but stands by it.
“Is it absolutely foolproof? I can’t say that,” Sherwood said in a phone interview on Aug. 3.
But he remains confident that Colbert’s team has found the right man.
“I am 100 percent sure beyond a shadow of a doubt that Robert Rackstraw is D.B. Cooper,” he said.
Sherwood also decoded encrypted messages in five other letters the team believes the skyjacker penned.
The fifth letter contained a random series of numbers and letters at the bottom, which Sherwood said corresponded to Rackstraw’s experience and Army units during the Vietnam war.
Double-checked against the methodology, the numbers all panned out.
While Sherwood’s errors with the sixth letter won’t instill confidence among the band of citizen sleuths known as Cooperites — some of whom are skeptical of Colbert’s conclusions — the methodology has gained the confidence of an FBI agent who worked part of the Cooper case.
Now a criminal-science professor at Western Illinois University, former FBI special agent Jack Schafer says he is impressed by the decryption.
“If this decoding is real, if they have documentation to prove and validate their conclusions, then this is very important, it’s very significant,” Schafer said in a phone interview. “And it could certainly lead to a solution.”
Schafer, who helped organize the search on the banks of the Columbia River where some of the $200,000 ransom turned up, was once skeptical of Colbert’s conclusions about Rackstraw.
The two have disagreed in the past about how the money ended up on the river’s shores. While Colbert thinks Rackstraw had some of the ransom money planted on the river bank Schafer, who says he relies on hard evidence, didn’t buy that theory.
“I couldn’t go along with it,” he said. “I said I don’t believe that’s how it got there. I believe it came there somehow and washed up.”
But that doesn’t detract from his views about Colbert’s ultimate conclusion that D.B. Cooper is Rackstraw.
“I think Tom has come up in the end with some very good evidence,” Shafer said.
Schafer believes that evidence is bolstered by the fact that the original 1950 coding manual, which explains the methodology, still exists.
According to Rackstraw’s former commander, retired Lt. Col. Ken Overturf, the manual says that the codes can be individually modified, which can make the code more difficult to crack.
“With his intellect and ingenuity, and having knowledge of the Army coding processes, Rackstraw would certainly be capable of modifying the processes,” Overturf said in an email.
“He would be perfectly capable of planning and executing a complex and successful hijacking and escape, as well as developing and modifying code processes for the purpose of covertly communicating with accomplices or harassing the media and FBI,” Overturf added.
Overturf recalls that Rackstraw was gregarious, but cavalier about his military duties. He was also talented.
“He was one hell of a good pilot and had no hesitation in performing challenging and hazardous missions,” Overturf said.
Rackstraw had volunteered to serve as a pilot in Project Left Bank after assuring Overturf he could get a top-secret clearance. That turned out not to be the case so Overturf relieved him of his flight duties six weeks later, when his clearance was rejected.
Looking back, Overturf says he thinks Rackstraw would not have hesitated to leap out of a Boeing 727 into freezing rain.
“I don’t believe that the FBI ever identified any other suspects that had the demonstrated unmitigated gall, guts and desperation to make that jump in those conditions,” he said.
But the FBI is not biting at the decrypted letters, much to the frustration of Colbert and his team.
According to Ayn Dietrich-Williams with the FBI’s Seattle Field Office, though the bureau is no longer actively investigating the case, it will still accept physical evidence related to Cooper’s parachute or the ransom money. But the decrypted letters simply don’t constitute the type of physical evidence the bureau will consider
And other Cooperites remain skeptical as well. Bruce Smith, a former investigative reporter who self-published a book on D.B. Cooper in 2016, says the evidence Colbert’s team has come up with – including the decrypted messages – is too circumstantial to prove that Rackstraw is Cooper.
“Rather than conducting a legitimate investigation, Colbert and his cronies are doing a Hoo-Doo investigation of letters that have never been proven to be from the skyjacker,” Smith said in an email. “The decoding crapola is just icing on a cake of turd.”