When Thomas roared those words, Batman and Cobblepot both froze.
Batman had not processed what he meant, while Cobblepot knew nothing about the previous murders and assumed Thomas was referring to Lex as the serial killer.
Thomas panted heavily and said in a hysterical voice, "This wasn't part of my plan! I didn't commit that murder. Things weren't supposed to turn out like this. I had everything planned..."
Seeing Thomas on the verge of breaking down, Batman realized this might be the best time to get the truth out of him. He looked at Thomas and asked, "You said your fiancée is in danger, and there's a serial killer. What's going on?"
Thomas's voice trembled. He seemed extremely reluctant, but he also knew Batman was the only one who could stop this now, so he said:
"I killed Doris. I borrowed a javelin from the sports equipment room, stabbed it through her chest, and killed her. But I didn't mean to kill her. I only wanted to use that case to..."
"...establish your alibi," Batman interrupted in a calm, steady tone. He continued, "You got yourself thrown into prison, then had your accomplice kill the Eliot couple to establish your alibi. After that, you planned to find a way to overturn your conviction, so you could walk out of prison innocent and inherit the Eliot Family."
"And the way you planned to overturn it was to have your accomplice continue committing murders similar to Doris's case, turning it into a serial murder case. That would prove you weren't the one who killed Doris."
Thomas froze. Then a teeth-gritting look of hatred appeared on his face, only to quickly turn into something more complicated. "Batman... Batman... you really are a genius. I should be too. I should..."
"Then what about your