Continuity mistake: When Lumen stabs Dexter with his knife in the swamp, she hits right above his elbow which he grabs promptly. When the camera angle changes, he's now grabbing his upper arm that's bleeding from a different spot than where he was stabbed.

Dexter (2006)
1 continuity mistake in Beauty And The Beast - chronological order
Starring: James Remar, Michael C. Hall, Jennifer Carpenter, David Zayas
That Night, A Forest Grew - S2-E7
Continuity mistake: When Deb meets Lila, Lila is at the fridge and puts her arm over her breast - she isn't wearing the 'engagement' ring. However when she returns to Dexter's room it's on her finger.
[MC Hammer's "U Can't Touch This" playing.]
Former Classmate: Come on, Dexter. It's hammer time.
Dexter: [internally] I have no idea what hammer time is. Or how it differs from regular time.
Trivia: (POSSIBLE SPOILER) When Masuka brings up the list of doctors authorized to get the M99, Dexter removes his alias note that Dexter's fake alias (used to get the M99 tranquilizer) is Dr. Patrick Bateman. Patrick Bateman is the lead character of "American Psycho". This was most likely an intentional "easter egg" of sorts within the show.





Answer: Two reasons. First, as a cop he knows that there are lots of murderers walking around free due to flaws in the system so he uses Dexter's "urges" to right the wrongs in the system by taking out people who have no right to walk around free. Secondly, by taking him to a psychologist he runs the risk of having him committed and he doesn't want that for obvious reasons, so he figures it is best to channel his urges to what he considers a greater good.
The_Iceman
In addition to the earlier answer, in the last season (8th) of the show, we are introduced to Dr. Vogel, whom Harry had been discussing the situation with Dexter as well, and it is shown on-camera that Harry describes what Dexter has done (killing)... So, technically he did consult a psychologist/psychiatrist, just not having Dexter and her actually meet. But Dr. Vogel was aware of whom it was and how to intercede.