Identification of Booth's body

[L Verge]

"True, the six personal letters went "missing" and have never been seen since they were supposedly found on the body, but the point is that federal officers on the scene swore that they found the six letters on the body."

Heard someone mention those letters years ago, but have never known the source of that statement. Please cite source and give direct quotes from those members of the Garrett Farm Patrol. Also list to whom the letters were addressed.