We have surprisingly fine-grained data on the religious affiliation of federal prisoners. I’m not sure why, but it might have something to do with the fact that a large portion of religious freedom cases in the US deal with prison accommodations (e.g. can a Sikh prisoner wear a beard? A Jewish prisoner have Kosher food? A Muslim have an imam with him during his execution, to name a few examples that have come up). 

The religious affiliations of prisoners are also raised a lot in the God wars since, while almost every study on the matter suggests that religiosity is negatively related to criminality, somewhat paradoxically atheists are actually quite rare in prison, so atheist influencer types love to trot out that number to counteract the stereotype that they are a bunch of Dostoevskian, God-is-dead-so-everything-is-permitted psychopaths. 

But for the purposes of this post we’re interested in another row–the Latter-day Saints. It’s worth noting that this is all self-report, so it wouldn’t include member-on-records-only cases like, say, Ted Bundy, but might include somebody like Ronnie Gardner. 

First, according to a 538 post, as of 2013 Latter-day Saints were the most underrepresented religious group besides atheists and, by a long shot–Pentecostals (I have no idea why the Pentecostals are so extremely underrepresented in federal prisons). Specifically, about 1 in 300 federal prisoners identified as “Mormon.”

Furthermore, a survey of Chaplains discussed in the same post suggests that on net more Latter-day Saints leave the faith in prison than join it, with 3% of the chaplains saying that the LDS presence grows in prison, and 11% saying that there are more people leaving the Church in prison. But the differences are small enough that I wouldn’t be surprised if it’s really a wash. (It looks like Muslims are by far the most effective prison proselytizers with a majority of chaplains saying that in their experience there are more Muslims converts than defections in prison, apparently  the Malcolm X-style in-prison conversions are not just a thing of yesteryear).

More recently, Hemant Mehta, an atheist influencer, put in another FOIA request for more recent data, which was broken down by race and gender. Specifically, in 2022 there were 455 total Latter-day Saint federal prisoners, 91% of whom were white and 96% of whom were male.