Lewis Powell's skull and Joseph Gawler

[SpruceCreekHawk]

On a slightly different tangent, I have been trying to determine whether Detective John Clarvoe was present at the arrest of Lewis Powell. Although some sources place him there, in John Surratt's trial it was testified that Clarvoe was with the group which headed off to Canada around 3 p.m. on Monday, April 17th but he got off the train around 11 p.m. in Philadelphia, where he arrested Celestino. It seems to defy the space-time continuum that he could have returned to Washington, D.C. in time to arrest Powell at the Surratt boarding house around midnight (or even the time of 3-4 a.m. on the 18th, as reported in the Daily Republican's extra.) Does anyone know of documentation which places him at Powell's arrest? Thanks!