Good.
You have your reasons. You have the experiences to have those kinds of reasons.
All I require is absolute certainty that the murderer is the one being executed. If that cannot be absolutely guaranteed, then I don't support the execution. When it can absolutely be guaranteed, then I have no problem with the execution.
If there was substantial physical evidence combined with sufficient circumstantial evidence supported by physical evidence, I would not have a problem sentencing someone to death. If the only evidence was eyewitness accounts, I would not sentence anyone to death, and would be very suspicious about the absence of any physical evidence, especially if the witnesses did not personally know the accused.
A larger problem is with prosecutors threatening more serious criminal charges than warranted only to get a defendant to plead guilty to a lesser crime even if the evidence of the lesser crime is weak at best.