I believe the passage from the book is along the lines of Joseph Smith and the early mormons tried to murder as many Indians as could in their travels west.
While several tribes were massacred in Utah it was long after Joseph's death.
I know of no armed conflict between mormons and Native Americans east of the Mississippi.
There was an incident between mormons, US troops and the Souix over a stolen cow near I believe Fort Laramie that led to an armed confrontation.
I believe Brigham's policy was to feed the Indians and avoid conflict when possible.
I don't know of any such killing by Smith. This is just my opinion, but I think he saw them as eventually becoming part of his army (cannon fodder) for his fantasy insurgent takeover of the US govt. This role is apparent from the BOM.
3 Nephi 20:16 -
"Then shall ye, who are a remnant of the house of Jacob, go forth among them [the unrepentant Gentiles]; and ye shall be in the midst of them who shall be many; and ye shall be among them as a lion among the beasts of the forest, and as a young lion among the flocks of sheep, who, if he goeth through both treadeth down and teareth in pieces, and none can deliver."
and 3 Nephi 21:12, essentially the same verse [more padding] -
"And my people who are a remnant of Jacob shall be among the Gentiles, yea, in the midst of them as a lion among the beasts of the forest, as a young lion among the flocks of sheep, who, if he go through both treadeth down and teareth in pieces, and none can deliver."
It's Young, of course, who engineered the killing. After arriving in the West, he viewed the natives as competition for scarce resources who had to be taken out (Timpanogos etc.), except for those who could be placed into servitude or used as handy scapegoats (Mountain Meadows).
There is also a chapter in the D&C that has the Native Americans rising up with the Saints in a war to destroy the United States. I also recall a couple or three instances in the D&C where God tells the Mormons to go West and take Native American women as wives. The whole point was that the Lamanites would become part of the restoration.
I wonder if anyone here is familiar with the Bernie Gunther novels by the late Phillip Kerr? Bernie is a super detective in the Berlin police force in the years before WW when Hitler was on the rise. Bernie is a rebel who despises the Nazi but self preservation takes him into the SS were he continues his detecting and obfuscation. During the process his adventures place him into contact with Nazi leaders like Goebbels and Heydrich and after the war with people like Peron and W. Somerset Maaugham. Their involvement is fictionalized into the plots and they fascinating dimension. Perhaps that is what the author is doing here. If he isn't what a wonderful device to explore past LDS leaders.
Good reads if you have not read them. I understand that an HBO series might be in the works with Woody Harrelson playing Bernie. Not sure about Woody but perhaps Kenneth Branagh.
Ah yes, moving Wallander south across the Baltic and giving him better luck with women. I approve!
Regarding the Gunther books, what's particularly cool is his remarkable fidelity to the history. Kerr was someone who went to great lengths to get the details right--I mean, Eichmann's trip to Jerusalem: who else would get that right?--and hence shed light on real events rather than just using them as a backdrop.
Wonderful stuff. I am sad that Kerr died so suddenly and there will be no more books. He was just 62. If you like Branagh check out a YT vid of him delivering the "speech" made by Colonel Tim Collins to his troops as they were about to launch the Iraq war. Amazing actor.
If you like that pre WW2 era in Berlin you might like the German crime series Babylon Berlin on Netflix.
Despite writing about them, Joseph Smith had surprisingly little interaction with Indians. He sent missionaries to them, but never lived among them, let alone learned any of their languages.
he went to visit the Indians in like 1830-31 with Oliver Cowdrey and others. This is when he had the revelation that the Elders were suppose to marry the Indians procreate and make them white and delightsome. This was the forrunner to plural marriage. The Elders squirmed at the idea and the revelation got hidden away until recently.
Steve Benson did an excellent post on that subject here on the site, somewhere.
Now on the other hand Brigham said to feed the Indians, but his policies were quiet different. The Mormon leaders purposefully sent Porter Rockwell to guide Colonel Patrick Conner to the Bear River where a battle took place and 300 Braves were killed. The largest Indian massacre in US history.