Maksim Gelman pleaded not guilty yesterday to four counts of murder after being accused of going on a 28-hour stabbing rampage, and court papers revealed he is confident he'll go free. The day after cops arrested him in February, he allegedly told a cop, "It's OK. I'll beat this. I'll go to a mental hospital for a few years and then I'll get out on the street again. You'll see." Unfortunately, he may be right.

This isn't the first time Gelman has worked to prove his insanity. Previous exclamations include, "I've had a doozy of a day. I did this because I have cancer," and, "I am the Mack, the guy you're looking for. The FBI gave me a raw deal." And when asked by investigators why he felt his victims had to die, he responded, "Because I said so."

Gelman is accused of killing his stepfather and stealing his car, then mowing down a pedestrian, killing his ex-girlfriend and her mother and then slashing a subway passenger before police finally arrested him. He has been held in the Bellevue psych ward because, according to him, "Sometimes, my mind isn't right."