Violent rapist Eoin Berkeley was the chief suspect in a double hammer attack eight years ago that left two women with fractured skulls and holes in their heads.
A young woman who survived the attack in a tower block in Ballymun in 2010 has said gardai identified Berkeley as the chief suspect.
She said he should have been taken off the streets eight years before he repeatedly raped a Spanish student in Dublin.
On Monday, Berkeley (25) pleaded guilty to the rape of an 18-year-old Spanish student.
Berkeley, who was on bail at the time of the attack, met the teenager in the city centre before luring her to a tent on the Irish Glass Bottle site in Ringsend and raping her repeatedly at a time unknown between July 15 and 16, 2017. She escaped after he fell asleep.
Despite being on bail after being charged with allegedly daubing homophobic graffiti on the facade of gay bar The George the previous May - a charge for which he was later cleared - Berkeley was not remanded in custody over a stand-off at his home in Hamptonwood Way, Finglas, on June 22, 2017.
This stand-off was dealt with under the Mental Health Act.
Speaking about her ordeal eight years ago, the young woman said: "Eoin Berkeley should have been locked up years ago and never have had the opportunity to rape that poor girl."
She described him as "an evil weirdo".
"I was 16 years old when I was attacked. I was going over to a friend's place in the tower block in Balbutcher. She lived on the 14th floor and when I arrived I took the stairs.
"It was about 6.30pm and I was going up towards the third floor when I saw a girl falling down the stairs and landing on her face.
"I thought she must have been fighting with her fella or something because I could see another young lad up there as well.
"I ran up to help her and then as I got to her out of the corner of my eye I saw someone swinging a hammer. It caught me in the side of the head above my temple.
"He just hit me the once and then I blacked out. When I came to I rang my friend and then I somehow made it up to the 14th floor.
"I knew it was a young fella who had attacked me, but I hadn't fully seen his face."
She continued: "When I got to my friend's apartment her ma saw the blood and straight away she rang gardai and an ambulance and me and the other girl were taken to hospital.
"She had been hit with the hammer as well and suffered a fractured skull, while the ligaments on one side of my jaw were torn.
"Afterwards the gardai told us he was the chief suspect - he lived on the fourth floor just above where I was attacked - and said a file was being sent to the DPP, but nothing came of it.
"I hadn't known him before that day, but people in the tower block knew him and knew he was just an evil weirdo.
"What happened to us was completely random because the other girl had no idea who he was either. It was only when I read what he'd done to that other girl that I knew I had to speak out because there were plenty of opportunities to stop him before he attacked her.
"Everyone in Ballymun knew what he was like and he should have been stopped back then."