In late February, a dog named Capone escaped from his yard in the city of Aurora, Colo. It was the only time in seven years living on the property, his owners said, that their fence could not contain Capone. The animal, a rescue dog his owners believed to be a German shepherd with black Labrador mixed in, made his way toward a nearby resident’s home.

He failed to charm the neighbors. “There was an aggressive dog in my backyard and he tried attacking us when we tried to get him off our lawn,” Diana Montoya told CBS 4. “He would just run to us and try to jump us.”

Aurora Animal Control captured Capone and held him at the local shelter. Animal control grew suspicious that Capone was not a typical dog — there was something wolfish about Capone’s character, behavior and body, they determined.

“The responding officer assessed the dog, which had been at the (neighbor’s) residence for five hours, and noted continued aggressive behavior, including approaching with bared teeth, low growling, hard stare and lowered head,” Aurora officials told the Aurora Sentinel in a statement.

From the outset, Tracy Abbato, Capone’s owner, disputed that her dog was part wolf. She also denied he was a threat.

“He’s not aggressive. Capone is a very mellow, laid back dog,” she said to Time magazine on March 16. “He’s a typical dog. He’s a family member. He doesn’t bother anybody.” Had Capone turned out to be part wolf, it was possible that animal control would have had him euthanized.

After catching the escapee, Aurora officials declined to release Capone to his family. They demanded that Abbato and her family wait until a genetic test could determine that Capone was not part wolf.

A DNA test later vindicated Abbato’s assertion that Capone was not a wolf. “The results came back negative,” she told Denver7. “Not an ounce of wolf.” On Wednesday, the Aurora Municipal Court cleared Capone to return home.

It marked the close of a nearly month-long separation. “It’s hard waking up and he’s not there,” Abbato said to CBS 4 on March 15. “It’s been heartbreaking. He’s our family member and we don’t have him here with us.”

A city ordinance bans animals or livestock that are wild, exotic or dangerous, which includes the unusual suspects — would-be owners of gorillas and crocodiles are out of luck in Aurora. Coyotes, foxes and wolves are banned, too. As are wolf-dog hybrids. Dogs are allowed, although pit bulls and certain restricted breeds were outlawed in 2006.

The city is wary of dangerous dogs. “It’s not just a wolf-hybrid issue by itself,” Michael Bryant, a city of Aurora spokesman, told Time. The 11-year-old dog bit a person on his family’s property in the past. Aaron Acker, an attorney for the dog’s owners, described the incident as Capone protecting against an intruder, Fox 32 reported.

Capone’s owners were charged with several offenses: keeping a wild and dangerous animal, not having a license for Capone, not vaccinating the dog against rabies and allowing the dog to roam unrestrained.

Republicans in Colorado’s state senate took up Capone’s case. “Big government is at it again,” read a post on the senators’ website. “An Aurora family is in danger of being split up because a local animal shelter suspects their family dog, Capone, could be distantly related to wolves.” More than 600 people signed the state Republican petition to spare Capone.

“I felt we should speak up for an animal who can’t speak for himself,” Tim Neville, a Republican state senator, told the Colorado Statesman. “We wanted to put attention on what appears to be local government overstepping and separating a pet away from its loving family and placing unnecessary charges against them.”

Those concerned about wolf-dog pet ownership cite the animals’ large size, high levels of energy and their unpredictability. A 1993 incident involving a wolf-dog who, although vaccinated, reportedly contracted rabies also raised questions about whether vaccines were as effective in hybrid animals.

A few hundred thousand wolf-dog hybrids are thought to live in the United States, although many wolf-dogs advertised as such are mislabeled dogs.

Wolf-dog behavior may be hard to generalize, said Kim Miles, a member of the wolf-dog advocacy group now known as the National Lupine Association, if the generational distance between wolf and dog is unknown.

“Wolf-dogs aren’t easily pegged because they’re essentially a combination of wild and domesticated animals,” Miles said to the Bark. “A dog is like a 12-year-old child, and a wolf is like a 35-year-old man. The dog will generally do what you want it to, but the wolf will do what you want only if he wants to do it himself.”

The animals can be difficult to keep as pets, too, because several states and municipalities outlaw the hybrids. (In D.C., for instance, it is illegal to own wolf-dog hybrids, cat-ocelot hybrids and other exotic pets. Whether exotic should be defined to include backyard chickens was a matter of recent debate.)

Although wolves and dogs are closely related, specific genetic differences may exist between wolves and their domesticated cousins. One test performed at the veterinary genetics lab at the University of California at Davis, for instance, checks for some two dozen short DNA markers that are unique to wolves. Such an analysis may be able to tell whether a dog had wolf great-grandparents, although tracing any wolfish lineage to older generations is difficult.

The University of California at Davis test, conducted with a sample of Capone’s blood, seemed to sufficiently absolve the dog of any recent wild ancestry. “We got some good news last night,” Abbato said Sunday to Fox 31. “Capone is not wolf at all. He doesn’t have an ounce of wolf in him.”

The Aurora Sentinel reported that Serrano pleaded guilty to three of five charges — failing to inoculate Capone against rabies, allowing him to roam free and not registering Capone with the city. After a hearing at the Aurora Municipal Court, Capone was able to return home as of Wednesday afternoon.

“We believe this resolution strikes a balance between keeping the family and their longtime pet together, and addressing the safety of the community as a whole,” Aurora Animal Services manager Jenee Shipman told the Aurora Sentinel in a statement.

The dog will return home vaccinated. And, as part of the resolution, Capone’s owners have agreed to construct a taller fence around their property.

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