A number of issues have not been researched yet at all, and this page will list a few of them.
1) The motive for the killing has been discussed already i.e., anger at the child followed by staging a sex crime for ethnic reasons. But that clearly would produce a lot of bloody clothing on the killer. Here is a defense lawyer trying to get info on clothing they appear to have researched.
2) This issue was brought up briefly by the defense, but was ignored by the jury due to the confusing hocus pocus logic the prosecutor used. One aspect of 'Ystr' vs 'str' DNA testing is that while str, or "short tandem repeat" is specific to an individual, Ystr is not. A male will have the same Ystr profile as his father, and also with all his male patrilineal ancestors, his paternal grandfather etc going back as many generations as passed since there was a significant mutation. So two male descendant first cousins of two brothers with the same father will have identical Ystr profiles, along with all their sons, and their sons' sons, on and on until there is a mutation at one of the alleles being looked at.
Most of the relevant testing was str, but there were some tests which used Ystr. The statistical numbers used to determine probabilities come from a United States sample collection and give numbers for certain ethnicities, but the actual probability arrived at by the witness at trial is dubious.
That specific witness has demonstrated several times his eagerness to help the prosecution, and this is an 'unknown' aspect of his testimony that probably should be questioned.
Ystr is useful in a case where there is a female victim because females do not have Ystr DNA since their DNA has two x strands and no y strand. So any Ystr you find will be from somebody else, a male, possibly the killer.
One example was the Ystr DNA under Hser Ner Moo's left fingernails in the audio clip above.
Among 25,787 random people in the United States, only 15 would be able to be included in that mix, as Esar Met was.
But if you went to a family reunion of Esar Met's paternal grandfather, in Burma or India or Thailand, all of the people who shared the same paternal lineage would have the same Ystr profile. In other words there are probably hundreds, maybe thousands of people with that same Ystr profile among Burmese and nearby populations.
At least a few people in the Salt Lake City Burmese population have that exact Ystr profile, i.e., Esar Met's brothers. And it's likely that people from his ethnic group, and possibly people from his paternal lineage, arrived in Utah before 2008.
The expert took that number based on a U.S. population i.e., 15 out of 25,787, and generated a 95% confidence interval that says there is a 95% chance 1 out of 1142 people in the United States could have been the person whose DNA was under Hser's fingernails as the part of that mix attributed to Esar Met.
If you were to test the Burmese in Salt Lake City of course there would be a much higher chance of finding somebody who had the same paternal lineage. The fact that other Burmese males had lived at that apartment shortly before Esar Met moved in, and may have still lived nearby, should be considered, along with other things.
That particular evidence probably was not related to the murder, but since it was used by the prosecution as murder evidence it should at least be examined properly.