Glenn was admitted in 1991 and worked as a lawyer for the State and Commonwealth governments until 2009 when he was called to the bar. He practised mainly in administrative, disciplinary / criminal and environmental law. Glenn has extensive experience before administrative and disciplinary tribunals and in boards and commissions of inquiry including inquiries into deaths.

Before coming to the bar, Glenn was the senior lawyer at the Department of Fisheries. He retains a particular interest in fishing, aquaculture and farming matters.