[2] Brendan went on to attend the University of Virginia School of Law where he was president of the Student Bar Association and a member of the Raven Honor Society.

He worked the night shift with tribal police officers, conducted leadership training for Native American youth, and implemented a new statewide community based prosecution strategy.

[9] Richard Hartunian, U.S. Attorney for the Northern District of New York, said "the efforts of the Dakota Boys were a turning point in U.S.-Tribal relations ... Brendan and Tim were the right leaders at the right time to carry out the vision of President Obama and Attorney General Holder to improve public safety in Indian Country".

Purdon and Johnson joined the law firm of Robins Kaplan LLP together and now work together on behalf of tribes in private practice.

In 2014, Johnson received Shared Hope International's Pathbreaker Award for determined leadership in combatting child sex trafficking: “Brendan Johnson is a force of determination, initiative and skill that should leave buyers terrified to purchase sex with a minor in South Dakota,” Shared Hope International President and Founder Linda Smith said.

“By creating a threshold for buyer accountability, he sets a national precedent that, if applied, will make significant strides in reducing tolerance for purchasing sex with a minor.”[11] After leaving the U.S. Attorney's office, Johnson went into private practice with Robins Kaplan LLP; he is the founding partner of the Sioux Falls branch.

[14] On November 4, 2019, Johnson turned in over 50,000 signatures for review by the South Dakota Secretary of State with the desire to qualify for the 2020 ballot.

"We are proud to have submitted petitions on behalf of over 80,000 South Dakotans who believe that voters should decide out state's marijuana and hemp laws," said Brendan Johnson, a former federal prosecutor and Democrat who is sponsor of the legalization ballot initiative.

[17] On November 20, 2020, Pennington County Sheriff Kevin Thom and Colonel Rick Miller, Superintendent of the Highway Patrol sued to block Amendment A from being implemented.