Editor's note: This is the first post in a series exploring violent crime in Denver.

Of the 58 murders that took place in Denver in 2017, more than twenty remain unsolved. And while firearms were used in the vast majority of cases, six people were killed by what are described as "personal weapons," including hands, fists, feet, arms and teeth.

The information comes from Colorado Crime Statistics, an excellent new website recently launched by the Colorado Bureau of Investigation. The site is very user-friendly, allowing folks to look up a wide range of data for specific time periods and jurisdictions.

We accessed Denver Police Department digits about violent crime, which includes murder, non-consensual sex offenses, aggravated assault and robbery, during 2017, the most recent year for which final stats are available.

Solving cases in these combined categories last year proved to be a significant challenge. Only about 54 percent of the DPD's cases were designated as "cleared," a term CBI communication director Susan Medina defines like so:

"'Cleared,' in most cases, means one or more arrests were made," Medina explains via email. "However, there are exceptions where an incident has reached a conclusion from the law enforcement perspective. An incident is also cleared if the offender is found but not arrested. These are called 'exceptional clearances.' Exceptional clearance occurs when the offender is a juvenile released to the parents, or if the offender is found to be deceased or if the offender is found to be in the custody of another jurisdiction. Also, an exceptional clearance may occur if the case cannot proceed by either prosecution declining the case or the victim refusing to cooperate. Then the incident is counted as cleared."

In all cases, though, "'cleared' means law enforcement has found the perpetrator of the crimes which occurred in the reported incident," she stresses.

When it came to murder, defined as "the willful (non-negligent) killing of one human being by another," the department was more successful, clearing 62 percent of slayings. CBI lists 36 of the 58 murders as cleared, leaving 22 unresolved.

Among the biggest surprises revealed by the data involves the location of the incidents.