Currently, Canberrans who die within 72 hours of an operation, surgery, or invasive medical procedure are automatically the subject of an inquest before the ACT Coroner.

The inquests are designed to uncover the manner and cause of death, and are able to identify failings of medical staff or others, and make recommendations for change where necessary.

But reforms expected to be introduced to the Legislative Assembly on Thursday will propose that only deaths that occur within 24 hours of a medical procedure will automatically become the subject of a coronial inquest. Attorney-General Simon Corbell has assured that deaths occurring outside that time limit could still be referred to coronial investigation where needed, and would still be the subject of internal scrutiny by ACT Health.

The changes are designed to reduce the total number of deaths that come before the ACT Coroner, as part of a broader drive to build efficiency and reduce court delays.

A recent review found that 16 per cent of all the ACT's deaths were the subject of coronial investigation in 2011, which the government said was the second highest rate in Australia.

Mr Corbell has proposed changes to the Coroners Act to cut that rate down to the national average of 10 per cent of all deaths.

He said it was important that only deaths that warranted investigation were subjected to an inquest.

''Deaths should only undergo coronial investigation and autopsy for good reasons, and then only to the extent that is strictly necessary to obtain the information the coroner requires,'' Mr Corbell said.

''A loved one's passing is traumatic enough without families and friends having to wait for unnecessary inquests to be carried out.''

Mr Corbell said the high rate of coronial inquests was due mainly to large numbers of healthcare-related deaths and non-suspicious, natural deaths, where no cause of death certificate was available.

The proposed changes would also make it easier for doctors to issue a cause of death certificate based on the deceased's medical history.

The current laws also require a coronial inquest where a person has not seen their doctor for three months before their death.

Under the reforms that period would be extended to six months. ''Avoiding unnecessary coronial investigation is fundamental to respecting the dignity of deceased people and their families,'' Mr Corbell said.

The government has also

proposed other changes to the criminal justice system.

It has proposed allowing summary offences to be dealt with in the ACT Supreme Court, at the same time as more serious, but associated charges.

That is designed to stop the courts from doubling up, and handling associated offences at separate times and jurisdictions.

The government has also proposed relaxing formal requirements for committal proceedings, which will allow the Magistrates Court to dispense with ''unnecessary requirements'' and allow the defence and prosecution to consent to a committal.

Mr Corbell said those changes were being made in response to issues identified by the Director of Public Prosecutions, the ACT Civil and Administrative Tribunal, and other justice stakeholders.

It was hoped the changes would lead to efficiency in the courts.