
How a Boulder County detective became one of America's leading cold case investigators
Steve Ainsworth spent over 30 years investigating homicides and major crimes for the Boulder County Sheriff's Office, examining more than 2,500 deaths and leaving an indelible mark on some of America's most notorious cases.
Quick Facts
Steve Ainsworth spent over three decades with the Boulder County Sheriff's Office Investigations Section, establishing himself as a leading authority on homicide investigation and death scene examination across the American West.
During his tenure, Ainsworth investigated more than 2,500 deaths of all causes and manners—a career marked by meticulous casework and an unwavering commitment to solving the unsolved. For the final 16 years of his time with the Sheriff's Office, he focused exclusively on major crimes against persons, with particular emphasis on homicides, cold cases, and fugitive investigations.
Beyond investigative work, Ainsworth became a sought-after instructor and mentor. He taught crime scene investigation at the Colorado Coroners Association Conferences, Wyoming Coroners Association, and Indiana State Coroners Association. Within his own agency and across Colorado's law enforcement training infrastructure, he led in-service programs on investigating death, robbery, and assault cases—the Colorado Sheriffs Training Institute and LEEPAC group among his training partners.
His expertise caught the attention of major case commissions and professional organizations. Ainsworth holds membership in the Colorado Association of Homicide Investigators, the International Association of Homicide Investigators, and serves on the State of Colorado Cold Case Homicide Review Team.
**The JonBenét Ramsey Connection**
Ainsworth's career intersected with one of America's most infamous unsolved murders: the 1996 death of JonBenét Ramsey in Boulder, Colorado. In 2001, Ainsworth and former prosecutor Trip DeMuth jointly stated that the investigation warranted a more aggressive pursuit of the intruder theory. The case—which involved trace DNA from an unidentified male found on the victim's clothing in 2003—remained open as of 2009, representing the kind of high-profile cold case that would define conversations about investigative strategy in Ainsworth's community.


