20 additional prisoners in the Arsenal ???

[BettyO]

As far as I know, the conspirators were the only prisoners housed at the Arsenal before and during the trial. Most prisoners, if suspected of spying and implication, were locked up in the Old Capitol, including initially, Mrs. Surratt and D. Preston Parr as well as the Branson ladies. Records for the Old Capitol DO exist. Those for the arsenal are only on record as far as I know in the Hartranft Letterbooks.