Two families lives were changed irreparably by the abduction and killing of Jastine Valdez, an inquest into her killer's death heard.
The jury recorded a narrative verdict last night in the case of Hennessy who died after being shot by a garda the day after Jastine had been abducted.
The officer, known as Garda A, had previously given evidence he believed Ms Valdez (24) was in the car and Hennessy was about to slit her throat. He said that "there was no other option open to me".
At the conclusion of the inquest, coroner Dr Myra Cullinane said this has been "most difficult for those involved and in particular the family of the late Mark Hennessy".
She said that the tragic events over 48 hours in May 2018 were "exceptionally unusual in this society".
The public were very moved by the plight of Jastine Valdez, and closely followed the garda response at that time, she said
"But the outcome has meant that two families' lives have been changed irreparably."
The coroner said that over the course of the hearing, "we have heard of brave acts on behalf of members of the public, and the assisstance of voluntary organisations and first reponders, sadly without the desired outcome".
She extended her condolences to the family of Hennessy (40), and said that the members who had attended the inquest, had been "dignified" in their grief. The inquest concluded last night after three days of evidence were heard.
It was told that the Hennessy family do not believe there was any malice involved in the shooting of Mark Hennessy.
"In relation to Detective Garda A the family are of the view that his view was reasonably held, that there was no malice in this situation," Dermot Hickey, solicitor for his parents said.
"The family wish to express their gratitude to the jury and all parties involved in this investigation, criminal and civil."
During his evidence, Garda A had told the inquest: "I was focused on Mark Hennessy and the actions within the vehicle. I was in great fear that Jastine Valdez was in the vehicle and she was in imminent danger."
Hennessy was prounounced dead at the scene of the incident on May 20, 2018 in Cherrywood Business Park.
The body of Jastine Valdez was located at 3pm on May 21, the day after Hennessy's death, in thick gorse and undergrowth at Pucks Castle, Rathmichael, Co Dublin.
On May 19, she had been abducted in broad daylight on a busy road at 6.20pm, after taking the bus from Bray to Enniskerry village arriving there at around 6pm.
An intensive search had been under way for the student.
Last night, after recording the narrative verdict, the jury also made a series of recommendations.
They said that in emergency situations there should be one central communications channel that provides information to all relevant personnel involved.
They also recommended emergency response training for all gardai.
Dr Cullinane said she would review the recommendations and draw them to the attention of the appropriate agencies.
Meanwhile, the inquest also heard that a post-incident manager position is to be created to deal with fatal firearm incidents involving gardai, to act as a conduit between the Garda Siochana Ombudsman Commission (GSOC) and the officer involved. The post-incident manager will be a member of the gardai.
The jury endorsed this development as part of their recommendations.
The system is not in place yet but has been operating well in the UK and will be adopted soon here, Garda Siochana Ombudsman Commission (GSOC) Senior Investigator Nicholas Harden told the hearing.