[2] Garcia won the general election to be Commissioner of Precinct 2 for Harris County on November 6, 2018, after advancing from the primary on March 6, 2018.

Garcia ran for re-election in 2022 and won the election against former Precinct 2 commissioner Jack Morman, with 52.6% of the vote.

[4][7] He has also served as a consultant for the U.S. State Department on the subject of law enforcement and policing programs in Central America.

[19] Additional programs that Garcia implemented included Mentoring Moms, that provided parenting mentorship to female inmates who were pregnant or had just given birth.

He also lobbied the legislature to reinstate mental health programs in the county, specifically geared towards crime prevention.

[20] In 2011, a 72-year-old inmate at the Harris County Jail died from complications of a heart attack after suffering physical trauma caused by correctional officers.

[21][22] In response to a public outcry over excessive force, Garcia fired two jailers and one deputy for failing to aid the inmate.

[25] In 2012, Garcia called for the continuation of 287g, a program that allows local deputies to ask individuals about their immigration status regardless of their crime.

[30][31] As late as April 24, 2015, Garcia claimed he knew "nothing" about Goodwin's condition until after the media got involved[32] after he attacked a prison official.

Upon his resignation, the Houston Chronicle wrote that, “commissioners would be doing the citizens of Harris County a disservice if they choose a successor eager to burnish his or her law-and-order, get-tough-on-crime credentials by undoing the progressive reforms Garcia has implemented in the large and unwieldy department he supervises.”[18] Prior to the campaign Garcia stated he supported the establishment of county-wide pre-K education as a method of future crime-prevention in addition to citing his bringing the Sheriff's department out of a $60 million deficit that existed before his term.

[40] During a September 2015 debate, Garcia faced questioning by his mayoral opponents regarding the role he played in one of the inmate abuse cases.