Denver police said a career criminal with a lengthy rap sheet and a previous murder conviction may be behind a string of violent break-ins and burglaries throughout the metro area.

Police believe Arthur “Art” Santistevan burglarized a home in the Cherry Hills Village neighborhood on March 17 before ramming a Cherry Hills police patrol car to get away.

Santistevan is also suspected of breaking into a business on Fillmore Street and stabbing a witness before fleeing.

Denver police spokesman Sonny Jackson said the suspect’s mode of operation during the March 17 burglary is similar to a number of other break-ins near East Floyd Avenue in Denver over the past three months.

“He's somebody that's got a long criminal history, and we're extremely concerned about him,” said Jackson.

Santistevan pleaded guilty to murder in 1981 and served seven years behind bars. He has also served time for burglary, drug possession, assault and parole violations. In 2007, the Denver district attorney reduced attempted murder charges against Santistevan to assault charges.

“He's faced the music,” said Jackson. “We've brought him before the courts, and he's done his time and he comes back out.”

One of Santistevan’s victims may have been Mandy Adams, who confronted a burglar in her grandparents’ house in February.

Adams said her Chihuahua began barking one afternoon when she walked into her grandparents’ house. She followed the dog to the bathroom, where she found the intruder.

“Against the wall in the shower was somebody,” she said. Adams said she instinctively tackled the intruder.

“I grabbed him and I threw him on the ground, and I tried to hold him there.”

The burglar, who she described as a middle-age Hispanic man, got away and ran down a hall. Adams said he punched her mother in the face several times before escaping through a window.

“We're pretty sure he's the man we're looking for,” said Jackson.

Adams could not confirm for certain that Santistevan was the burglar.

Police believe Santistevan may be staying with family members. Neighbors at a townhome on South Harlan Street in Denver, which is listed as Santistevan’s last known address, said they had seen him in the area recently, though relatives in the house denied knowing his whereabouts.

Jackson said Santistevan is considered armed and dangerous and urged anyone with knowledge of his location to call them.