Patrycja Szczesniak said she wishes she could turn back time to prevent the death of little Juliusz, who was shot, stabbed and smothered in his drink, drug and jealousy-fuelled father’s Edinburgh flat in November 2020.
IT worker Czapla 41, was jailed for life and ordered not to apply for parole for 23 years after he was found guilty of murdering his son.
A jury at the High Court in Edinburgh had previously heard the murder was sparked by his jealousy over Ms Szczesniak’s new relationship.
Following the verdict, Ms Szczesniak, said: "Every day I think about Juliusz. I can't imagine what his little, helpless heart felt that night and I feel his fear and pain every day. He was part of me, part of my heart and soul.
"I wish I could hug him, play with him and watch him grow.
"Every day I ask myself why there is so much evil in this world, why the innocent have to suffer.
"He not only took Juliusz’s life but my life too.
"That day, the world stopped, not only for me but also for my mother and my sister.
“Despite the breakup with Juliusz's dad, I wanted him to have contact with our son. I never stopped him seeing Juliusz. He loved him like every child loves their dad. He trusted him, he trusted him completely.
"Juliusz was murdered only for revenge. His dad wanted me to suffer, he succeeded and achieved his goal, at the cost of my beloved little boy’s life.
"If only I knew what was going to happen. I would have never thought he could do this to my child.”
Ms Szczesniak continued: “Juliusz was a very happy child. He lit up the place wherever he showed up. He could put a smile on anyone's face.
"It is breaking our hearts that we are no longer able to take his hand and lead him through life. To watch him enjoy riding his bike and eating his favourite ice cream. Listen to his giggling and laughing and being amazed by the things he learned every day.
"There was so much we wanted to show him but this chance was brutally taken from us and now the only thing we can do is to prey for the highest possible punishment. We want to believe in the justice system and that justice will be served, although I know there is no sentence that will bring my angel back to life.
"Czapla should not have the right to any defence and we will fight to ensure that monster never leaves prison.
"My suffering and my pain will stay with me for the rest of my life. But the unconditional love I have for my baby; my dearest child Juliusz will never end.
"My family, friends and l will miss him dearly and we will suffer his loss until the end of our days.
"Juliusz left us the most beautiful memories that will remain in our hearts forever."
Czapla admitted causing the tot’s death but denied murdering him. A guilty plea to the lesser charge of culpable homicide was rejected by the Crown.
Psychiatric experts could not agree if he was mentally ill and he admitted lying during an initial interview when he claimed to have no memory of the murder.
A jury saw through his ploy and took only three hours to convict him of him of shooting Juliusz with a BB gun before stabbing and smothering him.
The trial heard Czapla had repeatedly texted Ms Szczesniak the night before Juliusz was killed asking her intimate questions about her new partner.
She did not respond and Czapla spent the evening drinking beer then downed anti depressants with wine. He then decided to shoot Julius three times in the head with a gas powered air pistol.
Ms Szczesniak discovered her son’s remains the following day when she arrived to collect him.
Czapla, who kept quantities of LSD at the house at the same time he was looking after Julius, then left the property and drove off, committing road traffic offences as he tried to flee.
He claimed he suffered from poor mental health at the time of the killing and it affected his actions and he acted out of character.
Prosecutor Alan Cameron said the evidence before the jury showed Czapla was motivated by anger and jealousy over Ms Szczesniak's new relationship.
Jailing Czapla, trial judge Lord Beckett told him: “Your son will never grow up and his loving mother has lost him forever and will forever be haunted by the truly evil act that you did.
“You acted out of spite to punish his mother for leaving you and getting on with her life.”
“Suffice to say you showed considerable determination to ensure that a defenceless child would die in considerable distress.
“It is no excuse that you were full of drink and drugs indeed it is significantly aggravated given that you were being asked to look after a two-year-old.”
Thanking the jury and excusing them from duty for ten years, Lord Beckett added: “There can be nothing in your lives that could have prepared you for this experience and I don’t doubt that it perhaps has taken quite the toll on you listening to such dreadful occurrences such terrible violence inflicted on a young and defenceless child for no good reasons and for really bad reasons it seems.”
Outside court, Detective Inspector Bob Williamson, of Police Scotland’s Major Investigation Team, said: “Lukasz Czapla is now facing the consequences of his actions. The outcome of this case will never bring Juliusz back but it does bring this aspect to a close.”