history, and the succession of its several steps--few and summary. The
murderer was as yet altogether unknown; not even suspected. But there were
reasons for thinking that he must have been a person familiarly known to
Marr. He had entered the shop by opening the door after it had been closed
by Marr. But it was justly argued--that, after the caution conveyed to
Marr by the watchman, the appearance of any stranger in the shop at that
hour, and in so dangerous a neighborhood, and entering by so irregular and
suspicious a course, (_i.e._, walking in after the door had been closed,
and after the closing of the shutters had cut off all open communication
with the street), would naturally have roused Marr to an attitude of
vigilance and self-defence. Any indication, therefore, that Marr had _not_
been so roused, would argue to a certainty that _something_ had occurred
to neutralize this alarm, and fatally to disarm the prudent jealousies of
Marr. But this 'something' could only have lain in one simple fact, viz.,
that the person of the murderer was familiarly known to Marr as that of an
ordinary and unsuspected acquaintance. This being presupposed as the key
to all the rest, the whole course and evolution of the subsequent drama
becomes clear as daylight. The murderer, it is evident, had opened gently,
and again closed behind him with equal gentleness, the street-door. He had
then advanced to the little counter, all the while exchanging the ordinary
salutation of an old acquaintance with the unsuspecting Marr. Having
reached the counter, he would then ask Marr for a pair of unbleached
cotton socks. In a shop so small as Marr's, there could be no great
latitude of choice for disposing of the different commodities. The
arrangement of these had no doubt become familiar to the murderer; and he
had already ascertained that, in order to reach down the particular parcel
wanted at present, Marr would find it requisite to face round to the rear,
and, at the same moment, to raise his eyes and his hands to a level
eighteen inches above his own head. This movement placed him in the most
disadvantageous possible position with regard to the murderer, who now, at