For all those who might not know .. "entering a plea" is what the defendant does after he's been charged with a crime. Entering a plea of "not guilty" does not mean the person is saying they're not guilty.
The plea only means one thing: if you enter a plea of guilty - you appear before the judge and he administers judgment. If you enter a plea of not guilty - you have a trial before 12 members of a jury.
That's all it means. This guy is just going to take his chances with a jury - probably in hopes he can lie his way out of any real jail time.
Too bad they couldn't put the trial in the same location as Scott Peterson's trial...those folks have got a mighty fine sense of justice!