BOSTON—Law enforcement officials confirmed today that before the police captured Boston bombing suspect Dzhokhar Tsarnaev, the 19-year-old left a really nice thank-you note for the owner of the boat in which he had been hiding out that day. “To whom this may concern: Thank you very much for letting me use your boat. It was very nice to lie in,” Tsarnaev reportedly scribbled on the inside wall of the boat. “Anyway, I have to go get arrested now. But I just wanted to say thank you and that I apologize for causing you any trouble and for bleeding all over your boat.” According to sources, Tsarnaev signed the note “Yours, Dzhokhar,” and added a friendly postscript calling for the death of U.S. forces in Afghanistan and Iraq.