Long story short, he was a stay at home dad. She earned all the money and he did all the work at home. After they split, when he finally managed to earn some money, the amount of money that was required of him to give her was equivalent to 100% of his earnings.
One way she disappeared with the kid. He tried to search for the kid, putting "missing" signs around Warsaw. Later after they were found, the police considered his behaviour posting missing signs to look for the kid was "aggressive" and dangerous to the kid so he was severely limited from seeing his son and forbidden to take him to his own place (or anywhere else for that matter).
Before his death, he begged for help from people, wrote pleading letters but nobody listened and most people took the mother's side. Later him and his son were found dead. It was ruled as a murder-suicide despite suspicions of them both being poisoned.
Meanwhile, Polish "Daily Feminist" website made an article titled "even when a father murders his 4 year old son, women are guilty" claiming that a man killed his son (despite the fact that he was likely poisoned) and now people are blaming the mother. The details concerning the kidnapping and investigation and court decisions are of course omitted.
This is the same feminism that claims they "fight for men's rights", that blames the bias in courts or the idea that men are aggressive on "patriarchy". The same feminism that managed to turn a story of a stay at home dad having his son kidnapped, being forced to give 100% of his earnings to the kidnapper, kept away from his son because looking for him was deemed "aggressive" and then possibly murdered together with his son, into a story of "women are blamed even when men murder their kids".
Sadly I won't even say "imagine if the roles were reversed here" because it's not even possible, this would be impossible to happen to a woman. A stay at home mother would never lose custody of her kid. She would never be forced to give 100% of her earnings to the father. If a father were to kidnap is son and the mother looked for him, there would be a major campaign to find him demonizing the father as a horrible criminal (and rightly so to be honest) . And no way the courts would deem her "dangerous" or "aggressive" for posting signs looking for him. And lastly if there were suspicions of a mother being murdered together with her kid, feminist websites would be spreading it all over the media as proof of misogyny and a society that tolerates violence against women, not victim-blaming her.
All the sources are in Polish so for non-Polish speakers the best alternative is unfortunately google translate.
Translated by google:
Statement from the charity organization helping him: http://dzielnytata.pl/Majewski/stanowisko-DT-MF.pdf
Translated w/google: https://translate.google.com/translate?sl=pl&tl=en&u=http%3A%2F%2Fdzielnytata.pl%2FMajewski%2Fstanowisko-DT-MF.pdf