Just do the lines with the quotation marks: “Don't you get it?” he said. “She's not the thief. None of those four are the thief!” Eight pairs of eyes trained themselves on Eli as he explained. “None of us could have dug up the bush in the time since we saw it last,” he explained. “You’re looking at people who disappeared for what, ten or fifteen minutes? To dig up a full-size bush without damaging it? It would take hours!” He shook his head in disbelief as he continued. “Whoever stole the bush dug it up before we came! Then he just left it in the hole, with a little dirt on top to hide his work. With the bush already dug up, it must have taken him less than a minute to actually steal it later on. And any of us could have left for a minute or two! No one would even notice we were gone!”

Just do the lines in quotation marks: “What if someone accidentally stepped on them, and then he was afraid he'd get in trouble for breaking these expensive glasses? What if he swept up the mess, and threw it out.” Jerry looked at the floor. “He wouldn't want someone to look in the garbage can and see the glasses, though,” Eli pointed out. “So he'd probably tie the garbage bag and take it out himself. Right, Jerry?”