Wouldn't it be weird if Hengist was always dead.
Perhaps not "always", as in "killed ten years ago"; the body might start to rot or something. Redjac would probably find it advantageous to possess the only real police officer on the whole planet initially - no need to kill him if it possessed him all the time. But then came these visitors from outer space, and Redjac saw the opportunity to do lots of nice murders and then dump them all on the newcomers. That would mean leaving Hengist's body for a time, so at that point Redjac would probably either sedate or otherwise incapacitate, or then kill, Hengist. Probably just the former at first - but the latter when it became clear that staying in the copper's body would no longer be advantageous. Which is why I think Redjac only killed Hengist when the audience saw him die, aboard the
Enterprise.
What do you think, who committed the murders in the physical sense? Was the first one done by Scotty's hand, or did the critter just daze Scotty and use Hengist's hand? Somebody would have had to deliver the knife to Scotty if he were the killer... In theory, the poor lass could have killed herself, too. If the critter fed on feelings of terror, what would be more horrible than seeing one's own hand stab oneself to death?
In the second murder, Scotty is by far the likeliest suspect, but in theory it could have been anybody - Hengist, some Joe Schmoe abducted from the street and quietly killed afterwards, whoever. But that'd require picking the lock, a seemingly unnecessary complication for Redjac.
In the third murder, neither Scotty nor Hengist were particularly close to the victim - was it McCoy at that time? Could the critter be so subtle as to leave McCoy unable to tell he himself had used the knife? Could it control multiple minds and bodies at once? Would it daze everybody and then take over the body of Scotty or Hengist, move to the victim and do the deed?
Timo Saloniemi