OWEN SOUND, ON - A man accused of killing five kittens while at an Owen Sound house party in June 2011 was acquitted.

The judge found "insufficient reliable and trustworthy evidence" to prove guilt beyond a reasonable doubt.

Tyler Morris, 19, pleaded not guilty to killing the kittens, as well as to mischief and to prowling at night.

"This is a very serious crime," Judge Julia Morneau said. "The death of five helpless kittens in a brutal manner is deeply troubling."

The kittens were found dead in and around an Owen Sound house on the morning after a booze-laden house party.

All kittens had head trauma and one cat's internal organs were exposed.

One was found inside the house, one outside it and three more across the road in a neighbour's yard, including one apparently draped over a fence post.

But Morneau found a lack of proof beyond a reasonable doubt because of problems with witnesses, most of whom had been drinking excessively, and none of whom saw the kittens being killed.

Jesse Watson testified he saw Morris smash a rock down on the stones in front of the house, where a dead kitten would later be found.

"If Jesse Watson was a reliable and credible witness his evidence could well lead to a reasonable inference when I consider the physical evidence that he heard and saw the accused striking a kitten with a stone on the outside front step," the judge said in a written statement.

"However, Jesse Watson is not a reliable witness. The animus he bears toward the accused is gravely concerning."

The judge said Watson's testimony was inconsistent and argumentative.

Morneau also noted Watson had been drinking alcohol and suffers from a brain injury that affects his memory.

The Crown argued Morris killed the kittens while intoxicated and very angry over being asked to leave after fighting with his brother.

Forensic testing found animal or bird blood on Morris's shirt.

Morneau said she couldn't be sure the shirt hadn't been laundered, which could have thrown off forensic testing.

Watson testified Morris was handling the kittens and making them meow during the party. He also testified he warned Morris that night not to hurt the kittens, to which Watson reported Morris smiled and said he wouldn't.

Morris didn't testify at his trial, but he told a police officer he remembered going to the party, drinking and fighting with his brother, but nothing after that.