A desperate father harassed a Tusla social worker for more than a year as he was trying to get in touch with his son and she was his only point of contact.
Georgel Gheorghescu (38) repeatedly rang the social worker, sent her numerous text messages and beset her at her place of work.
He lost contact with his son after breaking up with his partner and was trying to find him.
Judge Ann Ryan ordered a probation report as well as victim impact statements and adjourned sentencing to January.
The defendant, of Meadow Green in Clonsilla, admitted before Blanchardstown District Court to charges of harassment and threats to kill.
Sergeant Geraldine McManigan said that between August 2015 and September 2016 Gheorghescu made harassing telephone calls and text messages to a Tusla social worker.
The court heard that he rang her, sent her text messages and beset her place of business looking for her.
He also made threats to kill her and cause her serious harm.
In a separate incident, Gheorghescu also threatened to kill a neighbour at Meadow Green in Clonsilla.
In that incident, on September 26, 2016, Sgt McManigan said the defendant came out of his house holding a knife and threatened to kill his neighbour.
The defendant has since moved away from the area, his solicitor said.
The court heard Gheorghescu has 27 previous convictions, mostly for road traffic matters.
Defence solicitor Simon Fleming said his client is originally from Romania but has been in Ireland 11 years an it is now his home.
Mr Fleming said Gheorghescu had a volatile relationship with his ex-partner and the couple split in 2015.
She disappeared with his son, and for nearly a year he didn't know where they were.
Mr Fleming said Gheorghescu was trying to find him, and the social worker was his only point of contact. The defendant "wasn't himself" at that time and he wished to apologise for his behaviour, Mr Fleming said.
The court also heard Gheorghescu's partner had psychological difficulties and had since returned to Lithuania, where she had been hospitalised.
He now has sole custody of his son, Mr Fleming added.