# Polish cold-case murder arrest

> Live situation record from CLSTR: https://clstr.news/situations/polish-cold-case-murder-arrest
> Updated: 2026-08-14T06:00:00.000Z. Sources: 11. Developments: 3.

In July 2026, Polish authorities announced the arrest of 37-year-old Michał S. for the 2011 rape and murder of 13-year-old Iza Strzałkowska in Gdynia. The breakthrough in the 15-year-old cold case resulted from advanced genetic genealogy, where investigators used commercial DNA databases to identify relatives and generate a suspected perpetrator’s likeness. 

To avoid traumatizing the suspect’s family, the Archiwum X (X Archive) unit from the Gdańsk command conducted surveillance on Michał S.’s daily routine, eventually arresting him outside his home on 21 July 2026. He was subsequently placed in three months of pre-trial detention.

Following the arrest, online speculation suggested that the suspect’s current wife was the 22-year-old student who had provided a key witness statement years earlier. Gdańsk police officials, including Deputy Chief Anna Banaszewska, publicly rejected this theory, confirming that the wife and the former student are distinct individuals and urging the public not to spread the erroneous rumor.

## Timeline

### 2026-08-14: Poland: DNA genealogy leads to arrest in Gdynia murder case

Polish prosecutors revealed that genetic genealogy and DNA profiling led to the identification and arrest of Michał S. in the murder investigation of 13-year-old Iza in Gdynia.

2 sources. https://clstr.news/cluster/poland-dna-genealogy-leads-to-arrest-in-gdynia-murder-case

### 2026-07-26: Polish police refute claim suspect’s wife was key witness in 13‑year‑old Iza Strzałkowska murder

Polish police arrested Michał S. for a 2011 murder of 13‑year‑old Iza Strzałkowska and denied online rumors that his wife was the original student witness.

5 sources. https://clstr.news/cluster/polish-police-refute-claim-suspects-wife-was-key-witness-in-13yearold-iza-strzakowska-murder

### 2026-07-23: Michał S. arrested for 2011 murder of 13‑year‑old Iza in Gdynia

Polish police arrested 37‑year‑old Michał S. in July 2026 for the 2011 rape‑murder of 13‑year‑old Iza in Gdynia, using DNA‑genealogy matches.

6 sources. https://clstr.news/cluster/polish-suspect-micha-s-arrested-for-2011-murder-of-13yearold-iza

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Cite as: Polish cold-case murder arrest. CLSTR, https://clstr.news/situations/polish-cold-case-murder-arrest