Pc Terry, a father of two from Burnley, Lancashire, was shot as the unit practised in a disused factory in Newton Heath on June 9 2008.
An inquest held at Manchester Coroner's Court in March 2010 found Pc Terry was unlawfully killed.
Greater Manchester Police has admitted a health and safety breach over the fatal shooting of one of its officers in a training exercise.
Pc Ian Terry 32, was killed during a firearms training exercise at a disused warehouse in June 2008.
Pc Terry's family attended Liverpool Crown Court today as Chief Constable Sir Peter Fahy pleaded guilty on behalf of GMP to a breach of Section 2 of the Health and Safety at Work Act (HSWA).
Two GMP firearms officers, who cannot be named for legal reasons, each denied one count of a breach of Section 7 of the HSWA.
The officers, a sergeant and a constable, will stand trial on June 10 at Manchester Crown Court.
The force will be sentenced on March 20 and 21 also in Preston Crown Court.