He was born in Alabama then relocated to New Orleans as a child. Prior to becoming a NCIS Agent, he was a deputy sheriff.
LaSalle and Pride have worked closely with each other and were initially the only two NCIS agents in the New Orleans office.
LaSalle volunteers at the local hospital, as he described 'the kids keeps [him] honest and [his] head on straight' and he developed a habit of making miniature structures out of Lego sets.
He has a brother, Cade Lasalle who has mental issues, as revealed in Love Hurts, although he isn't in contact with him.