Ice queen killer Martha Herda taunted investigating gardai by sending a bizarre postcard from Poland with a penny coin attached to it while on bail.
"Keep up the good work, wish you were here, hope you catch the killer," read the card sent to Arklow Garda Station.
The sick card was not addressed to any individual garda at the station.
Concerned about such a strange postcard from Poland, gardai decided to investigate the matter and found that the killer's DNA was on the stamp that had been sent.
Gardai have no idea what the killer's motivation for sending the coin was, but they are sure it was a strange way of saying "who is boss" or something', a source said.
"She is a callous killer, who thought she would get away with this from the start. No one knows why a penny was attached to that postcard, but it was," a source said.
"This woman always played the victim but she really had zero respect for gardai or her victim as that postcard shows," the source added.
"Some people were thinking that the idea behind it was that she was saying she gives a penny for a life but who knows what that is about. It seems she went bananas that morning of the murder but nothing about her behaviour since then added up. She was 'Mrs Smiley face' when she signed on at the garda station."
Herda was sentenced to life in prison for murdering the man who loved her, Csaba Orsos (31), by driving him into a deep harbour, where he drowned.
The jury returned to court at 11.36 yesterday morning, having spent eight hours and 11 minutes deliberating. They had found her guilty of murder by a majority of 11 to one.
Herda showed no emotion as the registrar read out the verdict, but became emotional when the court rose for a number of minutes before sentencing. She was comforted by her legal team and a number of friends.
Herda wept uncontrollably as Mr Justice McCarthy signalled for her to stand while he imposed the mandatory life sentence. She was then led away from her friends by prison officers.
The Polish waitress of Pairc Na Saile, Emoclew Road, Arklow, Co Wicklow had been charged with murdering the Hungarian.
She pleaded not guilty and went on trial at the Central Criminal Court earlier this month.
The court had heard how Herda was a good swimmer and knew that her passenger could not swim, when she drove her Volkswagen Passat through the crash barriers at South Quay, Arklow shortly before 6am on March 26, 2013.
She escaped through the driver's window at the harbour but her colleague's body was found on a nearby beach later that day. A post-mortem exam found that Mr Orsos died from drowning and not from injuries related to the crash.
The trial heard that the handbrake had been applied before the car entered the water and that the only open window was the driver's.
The jury heard that Mr Orsos was in love with her. Herda told gardai that she didn't feel the same way, and that he had spent two years following her, phoning her and sending her messages.
On the day of his drowning, she showed them a love letter he had sent her the previous year.
She told detectives they were constantly arguing about their relationship and that they had been arguing in the car when she drove into the water.
A security guard had heard the car coming at speed from the town. He said that it had seemed to stop momentarily before picking up again. He heard nothing else for three or four minutes. He then saw and heard a woman screaming as she ran towards the town.
This was Herda and the gardai found her soaking wet and frothing at the mouth a short time later. She told them that there was someone in the water and that they had to help.
The search for her passenger began as she was taken to hospital. She told a paramedic: "He shouldn't have been there. I drove the car into the water".
She later told a garda that he was dead because of his love for her. She said it was 24 hours a day and that she couldn't take it anymore.
On the morning of the murder, CCTV footage showed her driving to where Mr Orsos lived at around 5.30am, and a witness heard the driver having a heated argument on the phone. Call records showed that she rang the deceased three times around that time and a postman found his front door wide open later that morning.