Part 226: (Hint 18)

"Yeah. It confirms George-aniki's purple statement saying 'Maria couldn't kill anyone'. Since she couldn't kill anyone, she can't be a culprit. So, Maria is also confirmed innocent."
"Since George and Maria are innocent, that also proves that their examinations of their parents' deaths were also trustworthy."
"That's right. No one will mistakenly confirm a death, and people who aren't culprits can't lie. So, the deaths of their parents have been confirmed, and those parents are also innocent."
"We've gotten rid of almost everyone... The answer is already clear, is it not...?"