Who was W.L. Mendenhall (1873-1933)?

(Update at Bottom)

While researching the California Birth Index for the surname Mendenhall, I came upon some prison records for an W.L. Mendenhall 

He looks like a very sad man! From the card, you can read that his name was W.L. Mendenhall (or John Turner in Illinois??)- was imprisoned in the San Quentin State Prison for arson commited in San Joaquin. He's 44 and a laborer. He's also missing his left hand. The date he entered the prison- 26 Apr 1918. 

I wanted to know more about him and mainly, to find out how I'm related to this Mendenhall.  

First stop- Newspapers. I was able to find one news article about the arson committed to put him in jail-- 

Stockton Daily Evening Record
25 Apr 1918

From the article, W.L. broke into San Quentin and set the prison afire and then confessed to the crime. He was a sick man...suffering from TB and had lost his left hand in a saw mill accident 28 years earlier! From the card above, it looks like W.L. doesn't stay in San Quentin, but dies in Mendocino on 25 Nov 1933. The only evidence I have of this death is stated on the card...not sure how accurate that may or may not be.

Now, to find out how I'm related....

Things I know:

Name: W.L. Mendenhall

Born: abt 1874 in Illinois

I was able to find his full name from his World War I Draft Registration Card he had done while at San Quentin in 1918- Wilbur Lee Mendenhall, born 17 Aug 1873

It also states that his nearest relative is a Mrs. W.F. Adams at 3010 Locust St. in St. Joseph, Missouri. 

Before researching this Mrs. Adams, I wanted to look at the 1880 U.S. Census Record. Since Wilbur was born in 1873, the 1880 census would be the first one he would be listed on. I did find a Wilbur Mendenhall, born abt 1873 in Illinois living in Belle Plain, Illinois but this is a completely different Wilbur...one that is already in my tree. This Wilbur died in 1912 in Iowa so they couldn't have been the same person. 

I tried to look in the newspapers around 1890 for a saw mill accident that took a man's life, but it was just too little information. I have no idea where he was living at the time or what mill he was working at. I know he was jailed in Omaha Nebraska in 1914 (per prison card above), but I couldn't find any information on that jail time. 

Next, I decided to look up this Mrs. W.F. Adams who turns out to be Amanda Melvin Adams ('nee Palmer), daughter of Samuel C. Palmer (1824-1894) & Sarah Jane Lashley (1824-1869). She was married to William Freemont Adams (1864-1942). 

When Wilbur listed Amanda as his nearest relative in 1918, she was living in Saint Joseph, Missouri with her husband. This was April. Amanda died in Nov of the same year. 

Because they were close in age, her being 3 years older, I assumed she might be an older sister or maybe a cousin...

I've searched many family trees and tried several different paths on her family tree but I just can't find the Mendenhall connection! Which is annoying, to say the least.

Below is a picture of Amanda- 

From Ancestry.com

I'm going to keep searching, but I'm going to leave this here in case someone can help! :) 

UPDATE:

After posting the above information, I got some feedback from some people on the Genealogy Squad (Facebook). I am embarrassed to say that I didn't think to check her siblings. Ugg...it happens though. Anyway, Amanda's sister Rebecca Elizabeth Palmer married James T. Mendenhall on 19 Aug 1873 in Adair County, Missouri. (Marriage record on Ancestry.com). Now, there's a few things about this....

1. Rebecca & James were much older than Amanda and her relative Wilbur Mendenhall. 

Rebecca (born 1853), James (born 1847), Amanda (born 1870) & Wilbur (born 1873). It wasn't uncommon in those days to have multiple children and have them span 20 years like Rebecca & Amanda.

2. Rebecca & James married 2 days before Wilbur was born. This makes me wonder if he could be their child and Amanda is Wilbur's aunt. This could be plausible but there is something bugging me about this- Evidence shows that Rebecca and James married 2 days after his birth and they married in Adair County, Missouri. Evidence also shows Wilbur being born in Illinois. Either one of these records is mistaken (more than  likely, it would be Wilbur's birth) or they are not his parents. 

3. I thought it plausable that Wilbur could be James' brother but they are 26 years apart in age and I find this super unlikely. Also, I still can't find much about James anyways, so even though I have a possible brother or father, I still can't trace back the linage, which is SUPER frustrating.