Mothman

Mothman starts out... essentially it's like another one of those ridiculously common ghost movies. Characters become targeted, some die mysteriously and survivors must discover how to survive.

The monster itself tends to emerge from whatever reflective surfaces are available to murder victims.

The protagonist is visiting and reporting on the town. Killing her first wouldn't raise any suspicions so naturally the monster goes around killing the permanent citizens first.

But things reach their lowest when the monster starts rampaging, ignoring the previously-established rules completely. This scene doesn't make sense in the context of the previous events and is likely caused by a rewrite. Another problem is the main cast; many were murdered without making any impression.