Gross was born in rural Maryland to a single mother, the middle of three children, and moved to Boston at the age of 12.

[4] As a patrol officer, Gross served in the Anti-Youth Violence Strike Force and the Drug Control Unit, and later was an instructor at the Boston Police Academy.

In 2010, he became commander of the Field Support Division, which includes the Anti-Youth Violence Strike Force and the School Police Unit.

[13] White was formally sworn in on February 1,[14] and two days later was placed on leave after court records documenting domestic violence surfaced.

[15] Gross, a conservative registered as an independent,[16] considered becoming a candidate in the 2021 Boston mayoral election, but stated at the time of his retirement that he decided against running.