From the Richmond Enquirer, 8/4/1862, p. 2, c. 5
ESCAPE OF A FEDERAL OFFICER FROM PRISON – Lieut. Marster, of the 38th New York Volunteers, effected his escape on Saturday night from the prison on Eighteenth street, where he had been confined, together with about two hundred other Federal officers, since the defeat of McClellan. Nothing was ascertained as to the mode of his escape. The entire building is free to the promenades of the officers, and, it is supposed that Marster slipped out of the doors on the first floors when the sentinel's back was turned as he patrolled his beat. Appropriate measures were taken to secure his re-capture.