The fact of the matter is the Smarts are a prominent Mormon family and the entire political structure of Utah, including the SLCPD has as their primary directive upholding the image of the Mormon church. I have no reason not to think the SLCPD wouldn't defer to Uncle Tom's wishes on this. The FBI is the wild card here, but I'm not at all sure they could get a sketch artist of their own choosing to work with Mary K despite the opposition of the Smarts, the SLCPD and the Mormon church. Maybe they could. You are showing your ignorance of both Mormon influence on the police and the police deference to wanting this case solved. While the Mormon church is the largest denomination in SLC, Mormons are no longer even a majority and definitely not a majority on the police force - based upon my one pesonal experiences related previously.
If you think for a minute that the church would cover up for the Smarts or any other evil doer, you are very mistaken.
You are very naive.