I think DNA has improved over the last several years. I know they can link people thru their kin folk. For example, a serial killer in LA (who was a cop BTW) was found when a family member(s) traced their DNA with ancestry testing kit. I don't think this level of tracking was available when Mike was murdered. I could be wrong. I'm not an expert on DNA.
No expert myself. I'm not sure all of the pieces were there, I think most or all were but too expensive to be practical and of course the databases of DNA were far smaller. I think back then it was more practical to exclude somebody with DNA evidence than it was to convict them and that still cost tens of thousands best I remember. I remember it being $40K then $20K in very roughly that timeframe but I may be a full decade off now, I never needed DNA work. It is still very easy to have other DNA contaminating the sample and while the police may be sure, it is hard to bring something in a courtroom unless the sample is solid or very close to it, and the chain of possession is clean.
I know that catching Mike's killer gets easier by the day. My main hope now is that he doesn't die and escape justice. I do believe he will be found. Mike's family would still have some closure but being a lot more old testament than new I am hoping to be able to see some punishment.
Hu