John Steven Marx was born to Joyce Donner on March 23, 1957 in Champaign, IL and succumbed to pancreatic cancer on October 16, 2025 in Littleton, CO.  He was adopted into the family of Dr. Hans Marx as a young boy. John graduated from George Washington High School in Denver and earned his bachelor's degree in marine biology from CU Boulder.

John retired after 20 years with the City of Westminster Police Department.  The plight of first responders remained a life-long passion, to the extent he established his personal consulting, training and resources business, the Law Enforcement Survival Institute, and a non-commercial organization, CopsAlive.com to create a community for first responders. The mission was "Saving the Lives of the People Who Save Lives".  He also published two books of the several he had wanted to complete on the subject. These books are titled "Armor Your Self™: How to Survive a Career in Law Enforcement" and "A Penny for Your Smile".

His career, international charitable work and love of travel found him in the Caribbean, Europe, the Middle East and throughout North America.

John's fervor for improving the difficult and challenging lives of world helpers was countered by his enthusiasm for everything and anything Disney. His hobbies and passions included scuba diving, magic, cycling, survival skills, travel, and his beloved yellow lab, Ashley. He was also a collector of many items including, but certainly not limited to: Disney memorabilia especially Mickey Mouse items, pennies, knives, books (over 5,000), movies (over 3,000), casino coins, etc.

He is survived by his wife Brenda Cartwright and many siblings, nieces, nephews and cousins from both his adopted and natural families.

John will be remembered and missed by many.

A celebration of life will be held on Saturday, November 15, 2025 at 2:00 pm at Arvada United Methodist Church 6750 Carr St, Arvada, CO 80004 with a reception to follow. Service will be livestreamed https://youtube.com/live/ov5u7fJHkac?feature=share . Feel free to wear bright colors in honor of John. Please RSVP at johnmarxcol@gmail.com .

ln lieu of flowers, please consider making a donation on John's behalf to Colorado Concerns of Police Survivors - Colorado Chapter (Colorado C.O.P.S) .