I pretty much have uncovered chapter and verse on this guy -- Capt. West as he was called elsewhere on this board, or more commonly during and immediately after the war, General West. His name was definitely Francis Marion West, middle name Marion, not Marvin, as I suspected. Born February 1839.

So he was busted in Audrain County in the first half of 1869 for the murder of William Wallace which took place during the Jim Jackson/F.M. West raid into Iowa in October 1864. After shooting West in the leg for attempting to escape after his 1869 arrest, the sheriff of Davis County, Iowa promptly hauled him up to Davis County. By November 1869 this case was moved next door to Van Buren County, Iowa.

I don't know what the legal maneuvering was that transpired, but it was swift and successful for West. Within weeks of being moved to Van Buren County West was back in Audrain County, got married there on March 23, 1870, was fruitful and multiplied, had 10 kids between 1871 and 1893, was living in Chariton County by 1880, and Custer County, Colorado by 1900. He died April 23, 1907 at the age of 68, and is buried in Pueblo, Colorado (findagrave here: https://www.findagrave.com/memorial/119924186/francis-west )

While I can't say for certain how he got off the hook (that would require looking through Van Buren County, Iowa, court records between Nov. 1, 1869 and March 22, 1870, if said records still exist) but I can make an educated guess regarding what happened--

1) Francis Marion West aka Frank West aka F.M. West aka General West had taken the oath at some point around the close of the war, and was covered by a general amnesty;

and/or

2) He had a strong argument for a case of self defense. In my research I discovered West had appeared at the farm of William Wallace and asked about any livestock he had to sell. Wallace sent him on over to a neighbor. Shortly afterward Wallace was approached by individuals asserting a suspicion that a guerrilla had just past through the area. Wallace told them about his contact with West. The individuals went into town to obtain military and law enforcement to confront West at the neighbors. In the meantime, Wallace, his son, and a third man armed themselves and went in heavy to the neighbors house attempting to take West into custody themselves. It did not go well for them. Wallace was killed, and the son was wounded.

West was living openly in Audrain County in 1869. Enter the sheriff from Davis County, Iowa, who enlisted the aid of a prominent St. Louis detective, with both going in and arresting him. West later said the reason he tried to escape after they took him into custody, and was shot in the leg in the process, was because he thought they were there for revenge, were going to take him out into the brush and execute him, and was surprised when that wasn't his fate.

Anyway, Capt. West, or Gen. West, a name he was still being referred to for a few years after the war, had a colorful but brief final post-war adventure, and then faded into obscurity.

Note, as suggested above he went by Frank West on occasion.

He did have four brothers, three of whom were old enough to have ridden with guerrilla or Confederate outfits and which I am wondering about--

James Hamilton West 1830-1871
Isham/Ishom West 1833-?
John A. West 1837-1907

The fourth brother--William E. West, was born in 1855 and was far too young to have been involved in the war.

And I note there was a Dick West who figures somewhat prominently in Noted Guerrillas, and other guerrilla accounts.