Errores

It is extremely unlikely that Bishop - or any police chief - would arrest Dexter on the fact that Matt Caldwell's leg screws were in Dexter's burnt home when, by her own admission, it was clearly an arson. At most, she would merely question Dexter hoping to garner more evidence or a confession.

The rifle Harrison uses in the last episode should have burned up in the fire that destroyed his home. Instead, it is unsinged.

Despite arresting Dexter for murder, a police officer would not draw her weapon on him the way Bishop does (while using another officer for backup with his gun drawn) if he was behaving peacefully as he does and posing no threat to her or anyone else.

The methods she uses to affect an arrest are up to her.

When Harrison is driving the truck through the town, the truck turns to the right at an intersection. The next shot shows Harrison turning the wheel to the left.

The next shot shows Harrison returning the wheel to the center position after the right turn.

The arrest of Dexter is on shaky legal grounds due to no chain of custody (titanium screws), no forensic evidence outside a couple of meaningless needle sticks, no witness testimony, no motives and only circumstantial evidence relating to means and opportunity.

After the arson, Chief Angela Bishop conducts an illegal and improper search of Dexter's property. The screws should have had a marker, been photographed, and then gathered with gloves to prevent contamination. Also, the screws from Matts leg were not "in plain sight", they buried under the blackened charred remains of the house. She also showed Dexter the screws in her hand - when they should have been kept in the Evidence bag in order to protect the chain of evidence. Subsequently, this discovery would have been thrown out as evidence in any court of law, and Dexter would have been free to go.