Three men have appeared before Leeds Magistrates' Court charged in connection with the robbery in which Pc Sharon Beshenivsky died.
Pc Sharon Beshenivsky was shot while on duty in Bradford last year
Raza Haq Aslan, Faisal Razzaq and Hassan Razzaq, all 24, were arrested in London on Wednesday.
Pc Beshenivsky was investigating a robbery at the Universal Express travel agents in Bradford in November when she was shot.
The trio were remanded in custody accused of conspiracy to rob.
Hassan Razzaq, of Serbert Road, Forest Gate, east London was refused bail but his brother Faisal, of the same address, did not make an application.
In a separate hearing, Mr Aslam, of St Pancras Way, Kentish Town, north London, was also remanded in custody.
The three men will next appear before Leeds Crown Court on 13 February.
A fourth man arrested in Leicestershire on Wednesday has been released.
The 38-year-old police officer was killed as she investigated an armed robbery at the travel agents in Morley Street, Bradford, on 18 November.
Her colleague Pc Teresa Milburn, 37, was also injured in the shooting.
Yusuf Jama, 19, and Muzzaker Imtiaz Shah, 24, have already been charged with murder and are awaiting trial in June.
Detectives are continuing to search for 25-year-old Mustaf Jama, who is wanted in connection with the shooting.