BRIDGEVILLE, Pa. George Sodini seethed with anger and frustration toward women. He couldnt understand why they ignored him, despite his best efforts to look nice. He hadnt had a girlfriend since 1984, hadnt slept with a woman in 19 years.

Women just dont like me. There are 30 million desirable women in the US (my estimate) and I cannot find one. Not one of them finds me attractive, the 48-year-old computer programmer lamented in a chilling diary he posted on the Internet.

For months, he also wrote vaguely about using guns to carry out his exit plan at his health club, where lots of young women worked out.

On Tuesday, Sodini put his plan into action. He went to the sprawling L.A. Fitness Club in this Pittsburgh suburb, turned out the lights on a dance-aerobics class filled with women, and opened fire with three guns, letting loose with a fusillade of at least 36 bullets.

He killed three women and wounded nine others before committing suicide.

He just had a lot of hatred in him and (was) hell-bent on committing this act, and no one was going to stop him, Allegheny County Police Superintendent Charles Moffatt said Wednesday.

The 4,610-word Web diary appeared to be a nine-month chronology of his plans to end his misery with a shocking act of carnage at the health club. He portrayed himself as painfully and inexplicably lonely.

Every evening I am alone, and then go to bed alone, he wrote. I see twenty something couples everywhere. I see a twenty something guy with a nice twentyish young women. I think those years slipped right by for me. Why should I continue another 20+ years alone?

It was unclear when the Web diary was posted and whether it had been updated online repeatedly since November or posted in its entirety recently. Moffatt said investigators are trying to determine whether anyone saw it online before the rampage.