Hightower is the alias of an agent working for Intex. He appears in the introduction of Gunpoint, where he shoots and kills Selena Delgado.
He will appear in the final level if the player chooses the job Rooke: The Killer. If he is in the level, then he will be at the top floor of the building, watching the stairs. Hightower does not count as a witness.
When the player ascends the stairwell, Hightower will pounce Conway, sending the two flying out the window onto the ground. Hightower will then punch Conway repeatedly.
When Hightower is punching Conway, the screen will gradually turn fade to black. Conway can try to incapacitate Hightower by punching back, or he can kill Hightower by shooting him, and either method will unlock an achievement. When punching back, Conway will slightly rise his head from the ground - once the screen is almost completely black, Conway's head needs to be slightly up for him to knock Hightower out, otherwise Hightower will incapacitate Conway.
Whatever the player does with Hightower in the final level does not affect the level's violence score.