DENVER -- The person or persons who are mutilating pets in Denver and Aurora are killing them with an almost surgical precision and that is worrisome to psychologists and animal lovers, 7NEWS reported.

So far there have been 10 cats, a squirrel and a rabbit that have been killed and left out for viewing since July 19, authorities said.

All were dissected in a surgically precise way, and some had their organs removed and their bloodless carcasses left near their homes, pet owners and neighbors said.

Investigators don't have any suspects, but they are looking to build a profile of such a person, 7NEWS reported.

Cherry Creek schools psychologist Bill Porter said authorities have consulted with him about the killings.

"The precision and the frequency have everyone most concerned," Porter said. "They're doing surgery on these animals."

Such cases are worrisome because, frequently, people who show such severe cruelty to animals go on to commit violent crimes against people, said an investigator with the Denver Dumb Friends League.

That is little consolation to an Aurora woman whose cat was among those that were killed.

Two weeks ago, Carol De Young's 13-year-old tabby cat, Mozart, vanished from her home. She didn't know what had happened until she received a call from Aurora animal control.

"They didn't really want me to see his body, so what they did was show me a picture of his head, and it was Mozart," De Young said.

She said her cat had slipped through a pet door, which it often did, and had been killed and mutilated. De Young said she cannot imagine the type of person who would do such a cruel thing.

"No more than I could imagine what went into Klebold and Harris and all the other serial killers because that's what this is like," De Young said.

"His loss has been like a big hole 'cause he was my only pet, and he was my good friend ... I feel like I've lost a relative."

The Denver Dumb Friends League has posted an $8,000 reward for information leading to the arrest of the animal killer, or killers. They would also like to hear of anyone in the within the last 6months to a year who has had a similar experience.

The city of Denver and Aurora are on the lookout as well.

"We want to be able to identify our perpetrators and get them some prevention and intervention and appropriate treatment before it escalates," said City of Aurora spokeswoman Cheryl Conway. "Obviously, we're going to advocate that people keep their pets indoors, particularly their cats."

Mozart's owner has learned that lesson painfully.

The city asks people who find bodies of animals to report that immediately, since there may be more victims that authorities don't even know about.