This is the one and only hero knife used in the sequence where Dexter kills Stan Liddy. It can be seen in season 5 episode 12. I included a couple of stills that I used to screen match the knife to the one used on screen. The tape wrap on the handle makes it easy to match. 

All of my Dexter props were acquired directly from an Art Department head who worked on the series. Unfortunately, I cannot share the identity of my source. I will include a COA from my company Reel Relics guaranteeing the authenticity. No COA from Showtime will be provided. If you have any questions, please feel free to reach out.