JMO It may have been one of those half serrated half straight edge knifes. Straight edge towards the front and serrated towards the hilt. I imagine it would prove ideal for both puncturing and cutting. Cutting the neck first with the serrated part. Compromising the victims airway to lessen any potential noise they may make. Then I imagine go for the puncturing of the vital organs soon after.Sorry, graphic…Had a thought regarding wounds not matching. Could it be slice vs stab?
A slashed throat to one would provide the silence and a free hand to cover the mouth of the other for stabbing.