LOL, gotta love when all that is used against us, are a bunch of anti-mormon books and websites. Kinda like the liberals using the MSM as their sources for truth.
*claps*
Well, certainly there are many shades of the Pratt-McLean story, depending upon whom you cite. (I think the one thing they all agree on was that Eleanor McLean was separated from her husband, Hector, but not divorced). Also, most historians, LDS & otherwise, do link the Pratt murder as one of the escalating factors of Southern Utah Mormons to distrust--or avenge--a wagon train party from Arkansas.
As for the blood oath as being part of the LDS temple ceremonies doesn't need "anti-Mormon" sources:
“... omit from the prayer circle all reference to avenging the blood of the prophets.” (Apostle George F. Richards, Apostle, 2/15/1927, as cited by John Buerger, “The Development of the Mormon Temple Endowment Ceremony,” Dialogue: A Journal of Mormon Thought, Winter 1987, v. 20, no. 4, p. 55).
All you have to do is read the U.S. Senate history of the confirmation of LDS apostle Reed Smoot as senator & you'll see that this oath was part of the investigation into accepting Smoot.