EDMONTON - Jurors deciding the fate of an Edmonton filmmaker charged with murder are faced with a choice between the accused's words and the accused's word.

It's just one more paradox in the case of Mark Twitchell, a self-professed "Star Wars" and slasher-movie geek who, say prosecutors, used what he learned in the fantasy world to commit murder in the real one.

Twitchell, 31, is on trial in the death and dismemberment of Johnny Altinger, a stranger he admits he lured to a residential garage he was renting on Oct. 10, 2008.

Closing arguments are set for Monday, but both sides have already staked out their ground.

The Crown argues that Twitchell clubbed Altinger with a pipe, knifed him to death, cut up the body and dumped it in the sewer as part of a plan to become a serial killer not unlike his fictional TV-show hero Dexter Morgan.

Prosecutors also say that Twitchell planned to do the same thing a week earlier to another man, but the intended victim fought back and escaped.

The Crown has entered into evidence bloody knives and pictures of hundreds of bloodstains in the garage.

But the battleground evidence has been a 42-page document found on Twitchell's computer. It's the start of what Twitchell told jurors was a novel he hoped to have published. The names of the characters and locations were changed, he said, but the plot reflected actual events with his wife, his mistress, his intended victim and Altinger.

The document details the aborted attack on Gilles Tetreault and graphically describes the murder and dismemberment of Altinger.

The Crown says the entire document is true, a diary in essence, but Twitchell says the parts where he writes about intending to kill Tetreault and deliberately killing Altinger are false.

He has confessed to killing Altinger, but said it was an accident. He has pleaded not guilty to first-degree murder.

He told the six-man, six-woman jury last week that he lured Altinger, 38, to the garage, which he had dressed up as a pretend "kill room" with knives and plastic sheets around a table to catch blood.

But it was all a publicity stunt to help hype the short slasher movie he had shot two weeks earlier in the same garage, he testified.

The plan was for Altinger to show up, for Twitchell to tell him he was tricked and then to ask Altinger to write about being attacked by a knife-wielding maniac, just like in the movie. The result, Twitchell hoped, would be Internet buzz for his movie.

He said Altinger got angry when told of the hoax. The two fought and, in self-defence, Twitchell hit him with a metal pipe and knifed him to death with a large military-style blade.

Both weapons happened to be in the garage because they were to be used as film props, he said.

"That was a fortunate turn of circumstances," dead-panned Crown prosecutor Avril Inglis in her cross-examination.

"I understand how bad it looks, but yes," Twitchell replied.

Inglis persisted in trying to get him to admit his novel wasn't partly true, but all true.

"It was a vanity project," she suggested. "The plan to become a serial killer and make an account of it was purely out of ego."

Twitchell stared back, his hands gripping the wooden edge of the witness dock.

"It was a vanity project to prove you could lure people, kill them, and get away with it.

"Everything put before the court for the last three weeks proves (the document) to be true -- except for your testimony."

"I can't agree with that," he said.

During questioning, Twitchell's eyes became moist and his lip quivered when he recounted the death of Altinger, his decision to cut up and dispose of the body, then lie to police because no one would believe it was an accident.

Not so, suggested Inglis.

"You were acting when you teared up in front of the jury."

"I don't have those abilities," countered Twitchell, and for the rest of his testimony he stayed on an emotional even keel.

Twitchell said the idea for the luring hoax was part of a grander scheme to mix fantasy and reality on the web. It was a 21st-century marketing plan, he said, that sprang from his "savant power" -- a gift he said he can't control. He likened it to a faucet that turns on by itself and all you can do is put a bucket under it to catch the flow.

Inglis saved her most stinging criticism for emails Twitchell wrote to a friend after the death of Altinger.

"Suffice to say I crossed the line on Friday -- and I liked it," he wrote.

That, he testified, was not referring to Altinger's death, but to himself getting back together with an old girlfriend and kissing her in the back row of a movie theatre -- even though he was married.

"So when you wrote (the email) you weren't talking about killing Johnny, you were talking about kissing your ex-girlfriend," asked Inglis.

"That's what was on your mind days after a man died in your garage?"

"I was focusing on something positive," he replied.