[5] Grissom graduated from Willowbrook High School in 1972[6] and went to Johnson County Community College and then the University of Kansas where he earned a bachelor's degree in Science in 1977.

He was appointed the U.S. Attorney for Kansas by President Barack Obama in 2010, serving until April 2016, after which he joined the national Polsinelli law firm.

He had been a member of Eric Holder's Attorney General's Advisory Committee,[7] as well as becoming a panelist on the Brennan Center's Blue Ribbon Panel on the redefinition of federal prosecution priorities.

[9] As the U.S. Attorney for Kansas, Barry Grissom focused on civil rights enforcement and community outreach.

[10] During his tenure, Grissom founded the Kansas Civil Rights Symposium (which promoted efforts to improve community relations with law enforcement), the District's first Human Trafficking Working Group (which coordinated the work of NGO's with law enforcement to curb human trafficking), directed the District's Project Safe Neighborhood program (which targeted felons who unlawfully possessed firearms), and oversaw the District's Project Safe Childhood program (which targeted child sex offenders).