His interest lay in being somewhere else.  If he had nothing to do with the murder, no part to act, why not stay at home?  Why should he jeopard his own life, if it was not agreed that he should be there?  He would not voluntarily go where the very place would cause him to swing if detected.  He would not voluntarily assume the place of danger.  His taking this place proves that he went to give aid.  His staying away would have made an alibi.  If he had nothing to do with the murder, he would be at home, where he could prove his alibi.  He knew he was in danger, because he was guilty of the conspiracy, and, if he had nothing to do, would not expose himself to suspicion or detection.

Did the prisoner at the bar countenance this murder?  Did he concur, or did he non-concur, in what the perpetrator was about to do?  Would he have tried to shield him?  Would he have furnished his cloak for protection?  Would he have pointed out a safe way of retreat?  As you would answer these questions, so you should answer the general question, whether he was there consenting to the murder, or whether he was there as a spectator only.

One word more on this presence, called constructive presence.  What aid is to be rendered?  Where is the line to be drawn, between acting, and omitting to act?  Suppose he had been in the house, suppose he had followed the perpetrator to the chamber, what could he have done?  This was to be a murder by stealth; it was to be a secret assassination.  It was not their purpose to have an open combat; they were to approach their victim unawares, and silently give the fatal blow.  But if he had been in the chamber, no one can doubt that he would have been an abettor; because of his presence, and ability to render services, if needed.  What service could he have rendered, if there?  Could he have helped him to fly?  Could he have aided the silence of his movements?  Could he have facilitated his retreat, on the first alarm?  Surely, this was a case where there was more of safety in going alone than with another; where company would only embarrass.  Richard Crowninshield would prefer to go alone.  He knew his errand too well.  His nerves needed no collateral support.  He was not the man to take with him a trembling companion.  He would prefer to have his aid at a distance.  He would not wish to be encumbered by his presence.  He would prefer to have him out of the house.  He would prefer that he should be in Brown Street.  But whether in the chamber, in the house, in the garden, or in the street, whatsoever is aiding in actual presence is aiding in constructive presence; any thing that is aid in one case is aid in the other.[5]

If, then, the aid be anywhere, so as to embolden the perpetrator, to afford him hope or confidence in his enterprise, it is the same as though the person stood at his elbow with his sword drawn.  His being there ready to act, with the power to act, is what makes him an abettor.