Prior to his death Kleiman was IT support staff for a small county sheriff's department in Florida. He has no relevant expertise -- e.g. the only evidence of Kleiman ever writing any program ever was a simple visual basic script to automate checking the windows registry for forensic information. Literally the only thing remotely suggesting any connection is documents from Wright which are provably forged and created after Dave's death.

[Wright's forgeries tend to be extremely bad: Stuff like changing the year in emails but not fixing the day of the week and misspelling Dave's name -- in emails supposedly from Dave. Accidentally producing unmodified originals, citing laws that didn't exist until years later, using software versions that didn't exist until years later, referencing URLs on his own domain names that he didn't register until years later, accidentally producing "dave"'s private keys in discovery ... but they're also extremely numerous, so it's easy to get smothered under the total mass of them.]

Wright invoked his former friend in his scheme posthumously to solve a specific logistical problem: Wright himself can't program (certainly not in C/C++). So in his forgeries he included someone who couldn't contradict his stories so that Wright could beg off his inability to answer questions as "Dave did that part". Fortunately for Wright, it turned out that none of the eligible victims asked any hard questions. Unfortunately for Wright, Dave's family came after him for their share of the fortune Wright claimed they created together. Fortunately for Wright, Dave didn't actually help him (because neither had early involvement in Bitcoin). Unfortunately for Wright, all the easily proved forgeries in the case with the estate end up making it look like Wright is covering up the involvement to hide what he owes. Wright's frogurt is cursed, but also doesn't exist. (So that's good?)

Kleiman isn't the only deceased person that Wright involuntarily enlisted into his con-- Wright as also claimed that he was aided by Gareth Williams (some MI6 spy that was in the news at the time Wright started spinning this yarn) and David Rees -- an older academic who was disabled and unresponsive in a care home at the time Wright claimed to have been working with him.