Here Mr. Webster referred to the cases of Kelly, of Hyde, and others, cited by counsel for the defendant, and showed that they did not militate with the doctrine for which he contended.  The difference is, in those cases there was open violence; this was a case of secret assassination.  The aid must meet the occasion.  Here no acting was necessary, but watching, concealment of escape, management.

What are the facts in relation to this presence?  Frank Knapp is proved to have been a conspirator, proved to have known that the deed was now to be done.  Is it not probable that he was in Brown Street to concur in the murder?  There were four conspirators.  It was natural that some one of them should go with the perpetrator.  Richard Crowninshield was to be the perpetrator; he was to give the blow.  There is no evidence of any casting of the parts for the others.  The defendant would probably be the man to take the second part.  He was fond of exploits, he was accustomed to the use of sword-canes and dirks.  If any aid was required, he was the man to give it.  At least, there is no evidence to the contrary of this.

Aid could not have been received from Joseph Knapp, or from George Crowninshield.  Joseph Knapp was at Wenham, and took good care to prove that he was there.  George Crowninshield has proved satisfactorily where he was; that he was in other company, such as it was, until eleven o’clock.  This narrows the inquiry.  This demands of the prisoner to show, if he was not in this place, where he was.  It calls on him loudly to show this, and to show it truly.  If he could show it, he would do it.  If he does not tell, and that truly, it is against him.  The defence of an alibi is a double-edged sword.  He knew that he was in a situation where he might be called upon to account for himself.  If he had had no particular appointment or business to attend to, he would have taken care to be able so to account.  He would have been out of town, or in some good company.  Has he accounted for himself on that night to your satisfaction?

The prisoner has attempted to prove an alibi in two ways.  In the first place, by four young men with whom he says he was in company, on the evening of the murder, from seven o’clock till near ten o’clock.  This depends upon the certainty of the night.  In the second place, by his family, from ten o’clock afterwards.  This depends upon the certainty of the time of the night.  These two classes of proof have no connection with each other.  One may be true, and the other false; or they may both be true, or both be false.  I shall examine this testimony with some attention, because, on a former trial, it made more impression on the minds of the court than on my own mind.  I think, when carefully sifted and compared, it will be found to have in it more of plausibility than reality.