You are to consider the defendant as one in the league, in the combination to commit the murder.  If he was there by appointment with the perpetrator, he is an abettor.  The concurrence of the perpetrator in his being there is proved by the previous evidence of the conspiracy.  If Richard Crowninshield, for any purpose whatsoever, made it a condition of the agreement, that Frank Knapp should stand as backer, then Frank Knapp was an aider and abettor; no matter what the aid was, or what sort it was, or degree, be it ever so little; even if it were to judge of the hour when it was best to go, or to see when the lights were extinguished, or to give an alarm if any one approached.  Who better calculated to judge of these things than the murderer himself? and if he so determined them, that is sufficient.

Now as to the facts.  Frank Knapp knew that the murder was that night to be committed; he was one of the conspirators, he knew the object, he knew the time.  He had that day been to Wenham to see Joseph, and probably to Danvers to see Richard Crowninshield, for he kept his motions secret.  He had that day hired a horse and chaise of Osborn, and attempted to conceal the purpose for which it was used; he had intentionally left the place and the price blank on Osborn’s books.  He went to Wenham by the way of Danvers; he had been told the week before to hasten Dick; he had seen the Crowninshields several times within a few days; he had a saddle-horse the Saturday night before; he had seen Mrs. Beckford at Wenham, and knew she would not return that night.  She had not been away before for six weeks, and probably would not soon be again.  He had just come from Wenham.  Every day, for the week previous, he had visited one or another of these conspirators, save Sunday, and then probably he saw them in town.  When he saw Joseph on the 6th, Joseph had prepared the house, and would naturally tell him of it; there were constant communications between them; daily and nightly visitation; too much knowledge of these parties and this transaction, to leave a particle of doubt on the mind of any one, that Frank Knapp knew the murder was to be committed this night.  The hour was come, and he knew it; if so, and he was in Brown Street, without explaining why he was there, can the jury for a moment doubt whether he was there to countenance, aid, or support; or for curiosity alone; or to learn how the wages of sin and death were earned by the perpetrator?

     Here Mr. Webster read the law from Hawkins. 1 Hawk. 204, Lib. 1,
     ch. 32 sec. 7.

The perpetrator would derive courage, and strength, and confidence, from the knowledge that one of his associates was near by.  If he was in Brown Street, he could have been there for no other purpose.  If there for this purpose, then he was, in the language of the law, present, aiding and abetting in the murder.