From 1977 to 1981, Suthers served as a deputy and chief deputy district attorney in Colorado Springs.
From 1979 to 1981, he headed the Economic Crime Division of the district attorney’s office and co-authored a book on consumer fraud and white-collar crime.
During his time as a prosecutor at the local level, he tried cases ranging from drunken driving to first degree murder and from shoplifting to securities fraud.

In 1981, Suthers became a litigation partner in the Colorado Springs law firm of Sparks Dix, P.C.  He remained with the firm until 1988, at which time he defeated an incumbent to become the elected district attorney of the Fourth Judicial District.
He served as president of the Colorado District Attorneys Council in 1994-1995.
At the conclusion of his second term, Suthers returned to Sparks Dix in 1997 as senior counsel in charge of the firm’s litigation section.
He then ran for Attorney General in 1998 and lost 47.4% to 50%  to Ken Salazar.

In January 1999, Suthers was appointed executive director of the Colorado Department of Corrections by Governor Bill Owens.
In that capacity he managed a department of 6,000 employees and an annual budget of more than $500 million.

In August 2001, Suthers was appointed by President George W. Bush as United States Attorney for the District of Colorado.
He was unanimously confirmed by the United State Senate and assumed the position the week before the terrorist attacks of Sept. 11, 2001.
During his tenure as U.S. Attorney for the District of Colorado, he led the state's anti-terrorism efforts and his office prosecuted several high-profile white collar cases, including cases against executives of Qwest.

Following the election of Ken Salazar to the United States Senate, John Suthers was nominated by Governor Owens and confirmed by the State Senate as the 37th Attorney General of Colorado in January 2005.
Suthers served the remaining two years of Salazar's term before running for reelection in 2006.
In November 2006, Suthers won election to the Attorney General's Office, defeating challenger Fern O'Brien by nine percent.
During the same election cycle, the Republican candidate for Governor, Bob Beauprez, lost 56–40.

Despite being courted in 2008 and 2010 to run for the U.S. Senate, Suthers chose to run for re-election.
Suthers defeated his Democratic opponent, Stan Garnett, in 2010 election by a 13-point margin – the largest margin of victory in a two-way race in Colorado that year.
In both 2006 and 2010, Suthers received the endorsement of virtually every major newspaper in Colorado.
including The Denver Post, which called him a "tireless public servant".

Suthers served on the executive committee of the National Association of Attorneys General (NAAG) from 2007 to 2013.
He chaired the NAAG Criminal Law Committee from 2005 to 2007 and was a member of the U.S. Attorney General’s Executive Working Group on Prosecution from 2005 to 2015.
He served as the Chairman of the Conference of Western Attorneys General (CWAG) in 2009-2010.

In December 2008, Suthers personally argued before the U.S. Supreme Court in the case of Kansas vs. Colorado.
The issue was decided in favor of Colorado.

In June 2012, Suthers was awarded the Kelley-Wyman Award by the National Association of Attorneys General.
 It is the highest award given by the Association and is presented annually to the Attorney General who has done the most to advance the interests of the Association.
Suthers had been a principal negotiator for the state attorneys general in the National Mortgage Settlement in which the nations five largest mortgage services agreed to pay $25 billion in compensation for loan servicing misconduct.

Suthers was the second longest-serving attorney general in Colorado history.
Only Duke Dunbar, who served 22 years from 1951-1973, had a longer tenure as Colorado Attorney General.

Suthers has served as an adjunct professor at the University of Denver School of Law and as a scholar in residence at the University of Colorado Colorado Springs.
He also has held several bar association leadership positions, in
From 1977 to 1981, Suthers served as a deputy and chief deputy district attorney in Colorado Springs. From 1979 to 1981, he headed the Economic Crime Division of the district attorney’s office and co-authored a book on consumer fraud and white-collar crime. During his time as a prosecutor at the local level, he tried cases ranging from drunken driving to first degree murder and from shoplifting to securities fraud.
In 1981, Suthers became a litigation partner in the Colorado Springs law firm of Sparks Dix, P.C.  He remained with the firm until 1988, at which time he defeated an incumbent to become the elected district attorney of the Fourth Judicial District. He served as president of the Colorado District Attorneys Council in 1994-1995. At the conclusion of his second term, Suthers returned to Sparks Dix in 1997 as senior counsel in charge of the firm’s litigation section. He then ran for Attorney General in 1998 and lost 47.4% to 50%  to Ken Salazar.
In January 1999, Suthers was appointed executive director of the Colorado Department of Corrections by Governor Bill Owens. In that capacity he managed a department of 6,000 employees and an annual budget of more than $500 million.
In August 2001, Suthers was appointed by President George W. Bush as United States Attorney for the District of Colorado. He was unanimously confirmed by the United State Senate and assumed the position the week before the terrorist attacks of Sept. 11, 2001. During his tenure as U.S. Attorney for the District of Colorado, he led the state's anti-terrorism efforts and his office prosecuted several high-profile white collar cases, including cases against executives of Qwest.
Following the election of Ken Salazar to the United States Senate, John Suthers was nominated by Governor Owens and confirmed by the State Senate as the 37th Attorney General of Colorado in January 2005. Suthers served the remaining two years of Salazar's term before running for reelection in 2006. In November 2006, Suthers won election to the Attorney General's Office, defeating challenger Fern O'Brien by nine percent. During the same election cycle, the Republican candidate for Governor, Bob Beauprez, lost 56–40.
Despite being courted in 2008 and 2010 to run for the U.S. Senate, Suthers chose to run for re-election. Suthers defeated his Democratic opponent, Stan Garnett, in 2010 election by a 13-point margin – the largest margin of victory in a two-way race in Colorado that year. In both 2006 and 2010, Suthers received the endorsement of virtually every major newspaper in Colorado. including The Denver Post, which called him a "tireless public servant".
Suthers served on the executive committee of the National Association of Attorneys General (NAAG) from 2007 to 2013. He chaired the NAAG Criminal Law Committee from 2005 to 2007 and was a member of the U.S. Attorney General’s Executive Working Group on Prosecution from 2005 to 2015. He served as the Chairman of the Conference of Western Attorneys General (CWAG) in 2009-2010.
In December 2008, Suthers personally argued before the U.S. Supreme Court in the case of Kansas vs. Colorado. The issue was decided in favor of Colorado.
In June 2012, Suthers was awarded the Kelley-Wyman Award by the National Association of Attorneys General.  It is the highest award given by the Association and is presented annually to the Attorney General who has done the most to advance the interests of the Association. Suthers had been a principal negotiator for the state attorneys general in the National Mortgage Settlement in which the nations five largest mortgage services agreed to pay $25 billion in compensation for loan servicing misconduct.
Suthers was the second longest-serving attorney general in Colorado history. Only Duke Dunbar, who served 22 years from 1951-1973, had a longer tenure as Colorado Attorney General.
Suthers has served as an adjunct professor at the University of Denver School of Law and as a scholar in residence at the University of Colorado Colorado Springs. He also has held several bar association leadership positions, in
John Suthers