Andrew was born in Dunedin and grew up in Auckland. He holds a Bachelor of Laws and a Master of Public Management.

Andrew joined the New Zealand Police in 1997 and has worked in both frontline and investigative roles. Prior to his appointment as commissioner, he was Auckland City Area Commander, South District Commander, and the acting Deputy Commissioner: Strategy & Partnerships. He has served as the New Zealand Commissioner of Police since 3 April 2020. He has also spent time at the Ministry of Justice, having been seconded on a two-year term from 2016 to 2018 as the Deputy Chief Executive for the Ministry.

Andrew and his wife have three sons.