The Encrypted Massacre Investigation

Your cellphone rings in your pocket, a ringone you don't recognize... You pick it up and answer rather sheepishly.
A voice answers, altered slightly by a computer program.
"Hello, __(Your name)___. This is L."
You have heard the stories about L, the world famous detective who solved any case he came across, but the real L died during the Kira investigation a few years ago. This must be a replacement. L waits for your response. You...