T. J. Hooker - Season 2 Episode 8 Deadly Ambition

After a security guard is shot down when trying to stop a diamond vault robbery, the investigating detective is determined to prove that the guard had taken a bribe from the robbers and wants to nail him for aiding the thieves. The guard is an old friend of Hooker's who knows that his friend wouldn't have been involved. As he and Romano investigate to find out the true circumstances it seems as if the detective is willing to go to any lengths, including blackmail, to see that he is covered in glory for his busts and quickly fly through the ranks.