Warren has specialised in handling catastrophic injury cases arising out of accidents, medical malpractice, assaults and product liability for more than 20 years. He is a Fellow of the Association of Personal Injury Lawyers (APIL) and a member of, and assessor for, APIL’s Spinal Cord Injury Specialist Panel and Brain Injury Specialist Panel. He is  Chief Assessor for the Law Society Personal Injury Panel.

His expertise is widely recognised by his peers. Warren is a member of, and assessor for, the Law Society’s Personal Injury Panel and is endorsed as a leader in his field in both The Legal 500 and Chambers UK directories. In 2013, Warren was the winner of the Eclipse Proclaim Claimant Injury Lawyer of the Year and also won the UK Acquired Brain Injury Forum (UKABIF) Award for Inspiration in Brain Injury 2013. In 2014, he has been shortlisted for the Spinal Injuries Association Rebuilding Lives Award in Legal Excellence.

Warren also has significant experience in pursuing personal injury claims throughout the world, having conducted cases across Europe, Asia, Australia and the Caribbean. He has particular expertise with US claims and is a leading member of AAJ (American Association for Justice) as well as the past co-chair of the International Practice Section and immediate past co-chair (and founder) of the Spinal Cord Injury Litigation Group. He is the only UK solicitor member of the Melvin Belli Society (pre-eminent personal injury lawyers of America) and the National Crime Victim Bar Association of America.