How are Markheim's character traits revealed throughout Stevenson's short story "Markheiem"?

Three significant literary techniques Stevenson uses to
reveal Markheim's character traits in "Markheim" are the use of reflection, reminiscence
of past activities and his doppelganger. In the first, the presence of the hand mirror
gives Markheim an opportunity for a literal and metaphorical good hard look at himself.
In fact, while holding the mirror, he calls it a "hand conscience" thus indicating that
he is precisely thinking of how he could possibly be acting the way he is acting and
having the intentions that he has. (This has some similarities to Dostoyevsky's
Crime and Punishment when Raskolnikov is at Alyona's apartment.)
This reveals Markheim's sense of conscience, sense of right and wrong and true moral
guilt, even though he protests to himself that he feels no guilt over his choice and
act.

In a literary technique of flashback, Markheim later
reminisces about his earlier days when he had religious beliefs and was engaged in
religious activities; it was also a time during which he was a more moral person. This
shows Markheim's foundational character traits, the traits that were with him in the
beginning but have been trampled upon by hardships and
desperation.

The third literary technique Stevenson uses to
reveal Markheim's character traits is the doppelganger, which is a German word meaning
" href="http://dictionary.reference.com/browse/doppelganger">double-walker."
It is said to be an alternate but identical presence of someone, a projection of a
person's energy field. Markheim's doppelganger comes walking up the stairs and
encourages him to put aside his false conviction that since he is in desperate straits,
God will understand and forgive his reason for murder; encourages him to face the truth
about his evil side, to see how far he has actually
fallen.

The doppelganger reveals Markheim's character
traits of self-delusion and pride that make him think murder is all right for
him because he has special circumstances. It also reveals
that Markheim still possesses the values, morals and beliefs of his past when these
reawaken and he is led to truthfully and humbly confess and face his
execution.