They could use his DNA profile to see if any of his rape victims were impregnated by him. By the way, that's another reason that I'm pro-life: do people want to destroy living evidence of rape? These doctors and prosecutors should encourage girls and women whom are impregnated by rape to keep the babies, extract DNA from the mothers' wombs while they're in the womb, and use the DNA as evidence against the rapists, and then either let the women keep the babies or adopt them out, even to rape victims whom wanted children and were left infertile as a result of being raped.
As for my reaction to the DNA evidence and assuming that no evidence with Maskell's DNA on it was destroyed: "HOLY ****!" So, he had his friend do the hitjob, which would explain the bloody shirt, and either clean off his own ring or use another ring. His friend was basically a murder-for-hire hitman.
His victims must be wondering why the friend's long-since ex wife didn't come forward before. He was evil and shrewd enough, though to use his friend as a hitman was even more shrewdly evil.
Also, you don't take someone to a murder victim's body & further assault a victim of sexual battery if you weren't complicit. Maskell did. The assault of further battery and murder was, of course, the infamous "Do you see what happens when you say bad things about people?"
Incidentally, now that we know where Maskell's buried, I would not be surprised if someone tries to vandalize his grave. Many are still understandably angry.