High drama in an Edmonton courtroom late Tuesday afternoon as a jury found Mark Twitchell guilty of first degree murder in the killing of Johnny Altinger.

As the guilty verdict was read out, there was a loud sigh in the courtroom from the victim's family.

The jury spent about five hours deliberating before returning with the decision

Twitchell stood stoically, staring straight ahead, then sat down. After victim impact statements were read out, describing how the loss has affected Altinger's family, Twitchell was asked if he had anything to say.

He stood up and was silent for several seconds, before saying that he thought he had something to say but said he decided against it, given everything that was happening in the courtroom.

Twitchell bludgeoned and fatally stabbed Altinger in a Mill Woods garage in October 2008. Nearly two years later, some of his remains were discovered in a sewer in a north Edmonton alley near the home of Twitchell's parents.

Altinger's mother addressed the media outside the courthouse after the verdict was delivered.

"I'm so glad it's over and the jury did the right thing," said Elfriede Altinger. "I'm just speechless, I don't know what to say, just so relieved."

"To me, he's a psychopathic killer that we've taken off the streets of this city. There's no doubt in my mind or I think any of the investigative team that he would have kept on killing," said EPS Det. Bill Clark, a lead homicide investigator in the case.

Crown prosecutor Avril Inglis recognized the work of the Edmonton Police Service in helping to solve the murder.

"They did an extraordinary investigation right from the beginning of the investigation," Inglis said, adding that more than 100 officers were involved in the case.

During the trial, Twitchell, an aspiring filmmaker, admitted he killed Altinger, but said the deadly altercation was in self-defence when a publicity hoax for a movie went wrong.

For nearly a month, jurors heard dramatic testimony and viewed dozens of exhibits, including a key piece of evidence, SK Confessions, a document found on Twitchell's laptop which the Crown referred to as a "diary".

The Crown said the document is a description of Altinger's murder and an attack on a previous victim, Gilles Tetreault, who managed to escape.

A first degree murder conviction carries an automatic sentence of life in prison with no chance of parole for 25 years.

With files from CTV's David Ewasuk.