A man in his 20s who was killed in Kingswood was stabbed as he attempted to start his car to go to work.
A woman in her 30s was arrested close to the scene shortly afterwards.
Gardai are still trying to establish a motive for the motive.
One possibility being looked into by detectives is that the attack could have taken place because the man parked his car in the wrong parking space, RTE reports.
The man, believed to be a native of Tallaght, is thought to have been staying with somebody nearby.
His car wouldn't start when he came out to set off for work at 7am.
The man had opened his car bonnet and was trying to start the car when he was attacked and stabbed several times.
He tragically died on the street between the two cars.
Gardai don't believe there was any personal relationship between the woman and the victim.
They don't know if she even knew the man.
A garda spokesman said: "A male, aged in his late 20s, received fatal injuries as a result of the stabbing incident.
"His body remains at the scene. The Garda Technical Bureau is currently at the scene.
"The State Pathologist has been informed and we are awaiting attendance.
"The female, aged in her 30s, has been arrested on suspicion of murder and is currently detained in Clondalkin Garda Station under Section 4 of the Criminal Justice Act, 1984.
"An Garda Síochána are investigating all the circumstances surrounding the fatal stabbing as there is no known motive at this time.
"Gardaí are appealing to anyone who was in the Brownsbarn Estate and Kingswood area between the hours of 6am and 7am today 25th February 2020 who may have information in relation to this incident to come forward. Gardaí are particularly appealing to road users who may have camera footage. Anyone with any information should contact Clondalkin Garda Station on 01 666 7600, the Garda Confidential Line on 1800 666 111 or any Garda Station."
