From 1964, a series of atrocious crimes took place on the territories of the Dąbrowa Basin and Upper Silesia, continuing (with short interruptions) until 1970.

[3] The autopsy established that she had been killed by blunt force trauma to the head, inflicted with a heavy object, and the offender had hit her several times post-mortem.

[5] However, since Polish operatives had not yet encountered such a vicious criminal, a special summit was held in the second half of July 1965 by the provincial administration of the Ministry of Defence, which combined all the known cases into one investigation.

[2] Despite the fact that the authorities remained silent about the murders, rumours about the Vampire quickly spread, sending the local populace and that of nearby Silesia into fear.

While Gierek had little interaction with his niece, Jolanta's murder resulted in the apprehension and punishment of the criminal to become top-priority, and the Vampire was labelled public enemy number one.

[5] In 1968, the Polish authorities finally appealed to citizens of the voivodeship to provide any information that could lead to the arrest of the Vampire, offering a reward of one million zlotys.

[3] This consisted of compiling 483 known supposed characteristics of the Vampire, both physical and mental, which were then compared with those of the thousands of male residents of the Dąbrowa Basin.

[2] A mentally ill craftsman from Sosnoweic, Piotr Olszowy, confessed to being the Vampire when he was interrogated for the crime, but was released due to lack of evidence.

[2] In November 1971, the police received a letter from Maria Marchwicki, in which she accused her husband Zdzisław of abusing her and their children, and also claimed that he was the Vampire.

[2] Almost immediately after his arrest, the task force was split into two groups: those who believed that Marchwicki was guilty (chief among them being Gruba) and those who strongly doubted it (among these were Colonels Zygmunt Kalisz and Stefan Tokarz, Lt. Zbigniew Gątarz and prosecutor Leszek Polański).

Marchwicki himself denied responsibility, but behaved oddly at interrogations, talking about supposedly undisclosed murders, and when asked to sign the protocol, he wrote at the bottom that "this is all a lie".

At the same time, while he was a secret informant for the security service, Jan feared that Kucianka would report him to the rector Kazimierz Popelek, so he persuaded Zdzisław to kill her with his help.

[6] The hearing was chaired by Justice Władysław Ochman and prosecuted by Józef Gurgul and Zenon Kopiński; Marchwicki's attorneys were well-known lawyers Bolesław Andrysiak and Mieczysław Frelich.

The charges seemed sensible to the court, as he had a history of beating his family members, disrespecting police officers, embezzlement of public property and other offences.

Attention was drawn to the fact that Zdzisław Marchwicki had never pleaded guilty, and that he was identified only by people who thought he corresponded to the perpetrator's suspected profile.