Krist was born in Omaha, Nebraska. In 1980, he married Margaret Mary O'Connor.
Krist graduated with honors from Creighton Preparatory School in Omaha, Nebraska, in 1975. He attended the University of St. Thomas in Saint Paul, Minnesota, where he received a Bachelor of Arts degree in sociology in 1979. He obtained a Master of Arts degree in business administration and human relations from Webster University in St. Louis, Missouri in 1982.
Krist served in the United States Air Force from 1979 to 2000 and retired as a lieutenant colonel. He flew more than 100 combat sorties. Still an active pilot, Krist has flown more than thirty different fixed and rotary wing aircraft, logging more than 15,000 hours airborne.
During his 21 years in the Air Force, Krist held key leadership positions directing critical missions including the high visibility Looking Glass mission at Offutt Air Force Base in Bellevue, Nebraska. He scheduled operations and flew missions on the Looking Glass EC-135 aircraft, which was the Airborne Command Post for Strategic Air Command. At the time of his retirement he had flown all models of the RC-135 reconnaissance aircraft.
Among other operations, Krist served in both Operation Desert Shield and Desert Storm. His first Command was an operational squadron flying combat reconnaissance sorties over Southwest Asia. In 1997, he was appointed as Chief of Plans and Programs for the 55th Wing at Offutt AFB where Krist coordinated Wartime Plans and Logistics Movements of over 4,000 personnel and billions of dollars of resources in one of the largest Wings in the United States Air Force. In 1998, he was chosen as an Active Duty Air Force Advisor to then-Nebraska Governor Ben Nelson and the Adjutant General of Nebraska.
During his career Krist served as the Commander of two Combat Flying Squadrons and the Operations Officer in three others. His operational assignment locations included Keflavík, Iceland; Souda Bay, Crete, Greece; Riyadh and Al Kharj, Saudi Arabia; Shemya, United States; Aviano, Italy; Frankfurt am Main, Germany; Budapest, Hungary; Diego Garcia; RAF Mildenhall, United Kingdom; Istres, France; Okinawa Prefecture and Tokyo, Japan.
Krist is a recipient of the Air Force Air Medal, Meritorious Service Medal, Air Force Commendation Medal, and Aerial Achievement Medal among other honors. In 2014, he was inducted into the Nebraska Aviation Hall of Fame. In 2017, Nebraska Secretary of State, John Gale, appointed him to serve on the Honor a Veteran Honorary Steering Committee.
Krist was appointed to the Nebraska Unicameral Legislature by Governor Dave Heineman on September 11, 2009, to replace Senator Mike Friend. He won his election for this office in 2010 and was re-elected in 2014. Krist represents the 10th Legislative District, an area encompassing some of the northwest portion of Omaha, the entire City of Bennington, and a north-central portion of Douglas County. In 2015, senators elected him Chairman of the Executive Board of the Legislative Council and he also served as Chairman of the Referencing Committee.
His standing committee assignments in the Legislature include the Judiciary Committee, the Agriculture Committee, and the General Affairs Committee. He also serves on the Rules Committee and the Justice Reinvestment Oversight Committee.
In 2017, Krist expressed interest in running for the Nebraska governorship in 2018. He initially indicated that he might run against incumbent Pete Ricketts in the Republican primary. In July 2017, he stated that he would run as a third-party candidate, and that he would remain a Republican until the end of his term in the Legislature. In September 2017, he announced his candidacy, and stated that he would change his party registration to "nonpartisan" later that day.
Krist was a member of the board of directors for the Madonna School for students of exceptional needs in Omaha, Nebraska, from 1992 to 2008. He served as board president from 2005 to 2008. He is an active member in the local chapter of the Air Force Association and is a member of the 55th Wing Association.
Krist is currently the Contract Manager for the United States Army Corps of Engineers Northwest Division Aviation Program. He has served as a pilot since 2000 and the Chief Pilot since 2002. The Division Aircraft is based at Offutt Air Force Base in the Omaha District and also services the Kansas City, Missouri, Portland, Oregon, Seattle, Washington and Walla Walla, Washington districts.