On September 25, 2020, Sgt Ratana, also known as Matt, 54, was shot in the chest while a handcuffed suspect was being taken into custody at Croydon Custody Centre.
Louis De Zoysa, of Banstead, Surrey, was shot in the neck during the altercation and was taken to the hospital.
Mr De Zoysa, 25, entered a not guilty plea via video connection at Northampton Crown Court.
An intermediary aided the defendant, who was in a wheelchair with his right arm in a sling.
He pleaded not guilty by holding up a whiteboard with the words “not guilty” scribbled on it.
Mr. De Zoysa is currently a patient at St Andrews Healthcare, a brain injury facility located nearby.
A trial date has been scheduled for June 6 in Northampton.
Sgt Ratana, who was born in New Zealand, died just two months before he was eligible for retirement.
Sgt Ratana was regarded as a “talented officer” with a “big heart” by then-Met Commissioner Dame Cressida Dick in the days following his death.
