Investigators were satisfied there was a single discharge of a Garda weapon on the raid on a house in Dublin, a Gsoc spokesman said. File photograph: Dara Mac Dónaill

The Garda Ombudsman has declined to investigate a raid in 2017 during which an armed unit fired shots after entering a house through a window.

A public-interest investigation into the accidental discharge of a Garda weapon during a raid on a private residence was “not warranted”, the Garda Síochána Ombudsman Commission (Gsoc) has said.

The Emergency Response Unit (ERU) assisted the Criminal Assets Bureau (CAB) on November 8th last in searching 24 homes as part of an operation targeting organised crime.

ERU officers raided a target’s home in Cabra, Dublin, and video taken at the scene shows officers tying a rope to the front downstairs window of the house and pulling it out using a Garda vehicle.

Officers then enter through the opening using a ladder. After the first officer enters, carrying a ballistic shield and his handgun, a series of bright flashes can be seen coming from the room. The following officer recoils slightly before also entering the building along with his colleagues.

It is understood the first garda had some difficulties when entering and this led to him firing his weapon by accident.

“There was no public-interest investigation into this matter as, after weighing the circumstances of the incident and taking into consideration a wide range of other relevant factors, the commission decided that an investigation in the public interest was not warranted on this occasion,” a spokesman said.

Single discharge Despite the video showing several flashes, the spokesman said investigators were satisfied there was a single discharge. A Garda source suggested the additional flashes could be the garda’s flashlight reflecting off objects in the room.

Sinn Féin justice spokesman Donnchadh Ó Laoghaire has questioned the commission’s decision not to investigate the accidental discharge of a weapon in a private home.

Gsoc was alerted shortly after the incident in keeping with normal protocol. It made a “strategic information request” to the Garda and was told the incident involved the discharge of a single round. The commission made the decision not to investigate based on this information. It did not send its own investigators to the scene.

Mr Ó Laoghaire criticised the decision not to launch an investigation.

“I do not think it is a satisfactory situation that the body tasked with overseeing An Garda Síochána is in a position where it simply accepts the version of events given by An Garda Síochána and does not examine or investigate it itself,” he said.

“The discharge of a firearm, in a domestic dwelling, by a member of An Garda Síochána is a very serious matter. There are limited circumstances where it may be required. However, any discharge needs to be examined properly.

“A stray bullet in a house could result in serious unintended injury, or worse, so it is important that all such discharges are accounted for, and that the Garda Síochána Ombudsman Commission is satisfied that they are accounted for.”

A public-interest investigation can be launched in circumstances where Gsoc believes a garda may have breached regulations or committed criminal activity. It does not require a referral from the gardaí or a member of the public.