In Death Note, Light Yagami aspired to become the god of a new world, recreated in his own image of justice. But that meant drawing the attention of L, the world's top detective, and L had Light's own father, Soichiro Yagami, on his side. Light was suspect #1 before long.
L fooled Light with a trick on the news, sending a man named Lind L. Taylor to be his proxy. This stunt put L on Light's trail, but he needed hard evidence of Light -- as "Kira" -- in the act, and that meant installing cameras in the Yagami home to catch him. But Light wasn't going down so easy.
Light and L Spar With Hidden Cameras
L was desperate for evidence to settle the case, and he knew just what to do: set up dozens of hidden cameras and bugs in the Yagami and Kitamura households, since one of those homes housed the true Kira — L already knew that Kira was somehow getting intel from the police, and was likely a police officer's family member. So, over some objections from his task force, L ordered the installation, but Light's bedroom was already prepared for such a thing. The police left no evidence of their presence, or so they thought. Light knew right away that someone had visited.
Light had placed a slip of paper between his door and its frame, and if the paper fell, that would be a sign of intrusion. Light also tweaked his door handle a bit, and only he knew about it. Finally, he had set up a pencil lead in the door's hinges, meaning the police were savvy enough to replace the slip of paper, but they couldn't have known about the door handle and pencil lead. So, Light knew that the police had visited, as opposed to his mom Sachiko, or his younger sister Sayu, who probably wouldn't have noticed or replaced the paper slip.
Light knew that he was in plain view of L via the cameras, with his every action and word being monitored. Light clammed up at once, refusing to talk to Ryuk, his shinigami companion, and he acted like a perfectly ordinary student. No way could he just open up the notebook and start writing names. It was time to get sneaky.
Light Deploys His Infamous "Potato Chip" Trick
Light was sure that cameras and bugs were monitoring the rest of the house too, and he was right. He had already slain Raye Penber and the FBI agents in Japan, and L was anxious to avenge their deaths with this trick. Light, however, had an idea. He brought up a bag of potato chips for a snack while studying in his bedroom, and he hid a Death Note page in there, along with a tiny portable TV. During his study session, he would watch the news and see a criminal's name and face, then write one character of that criminal's name when he reached into the chip bag. This was a slow but covert way to kill a few criminals, and as far as L could see, Light was just studying while snacking. Three criminals died, and it seemed like Light never saw their names or faces on the news.
But that would almost be suspiciously perfect in L's eyes, so a few days later, Light openly watched the news at home, in a way that L could see via those hidden cameras. He proceeded to kill those criminals with his potato chip bag trick, and now, L could see that criminals were dying by Kira's hand whether or not Light had seen the news. Light wasn't obviously guilty, nor was he suspiciously perfect, meaning L couldn't make much of this at all. And what is more, Light had asked Ryuk to spot all the 64 cameras in his bedroom, so no camera would see inside the potato chip bag and peep Light's trick.
After a few more days of this, L reviewed all the camera footage, and was bitterly forced to conclude that he had no hard evidence of Kira activity from the Yagami or Kitamura households at all. So, all the cameras and bugs would be uninstalled, and L would have to figure out some new trick. Being his stubborn self, L didn't see this lack of evidence as proof of Light's innocence; instead, he decided (correctly) that Kira was still operating like usual, but hiding their methods. L was as stubborn as Light, and that was what led him to abandon his hidden cameras and follow Light all the way to To-Oh University to observe him in person. No more games with cameras and bugs; it was time for a man-to-man confrontation.
