Seweryn Antonowicz Kłosowski (14 December 1865 – 7 April 1903), better known under his pseudonym George Chapman, was a Victorian era Polish serial killer known as the Borough Poisoner.

He was convicted and executed after poisoning three women, but is remembered today mostly because some contemporary police officers suspected him of being the notorious serial killer "Jack the Ripper".

[1][2] According to a certificate found in his personal effects after his arrest, he was apprenticed at age 14 to a senior surgeon, Moshko (Mosze) Rappaport, in Zwoleń, whom he assisted in procedures such as the application of leeches for blood-letting.

[2] This course was very brief, lasting from October 1885 to January 1886 (attested to by another certificate in his possession) but Kłosowski continued to serve as a nurse, or doctor's assistant in Warsaw until December 1886.

[3] Kłosowski settled in the East End and became a hairdresser's assistant in either late 1887 or early 1888, with records indicating that he worked for an Abraham Radin of 70 West India Dock Road.

He stopped working there after five months, and he subsequently opened a barbershop at 126 Cable Street, St George in the East; this was also listed as his residence in an 1889 London directory.

However, bitter fights often erupted between husband and wife, culminating in an incident in February 1892 in which Kłosowski attacked Lucie while she was pregnant and threatened to kill her.

In 1893, while working as an assistant in Haddin's hairdresser shop, Kłosowski met a woman named Annie Chapman (no known relation to the Ripper victim).

That same year, he became an assistant in William Wenzel's barbershop at 7 Church Lane, Leytonstone, while lodging at the house of John Ward in Forest Road.

This business was unsuccessful, and they moved their shop to a more prosperous location and began offering "musical shaves", in which Spink played the piano while Chapman serviced the customers.

A woman who lived in the same building claimed to have often heard Spink crying out in the night and to have noticed abrasions and bruises on her face and marks on her throat.

After she began coming down with the same symptoms that Spink had shown, Chapman left London with her to avoid controversy, moving to the market town of Bishop's Stortford, Hertfordshire, where he ran The Grapes Pub.

Suspicions surrounding this death led to a police investigation, which found that Marsh and the other two women, whose bodies were exhumed, had died by poisoning.

[3] Speculation in contemporary newspaper accounts and books has led to Chapman, like fellow serial killer Thomas Neill Cream, becoming one of many suspects in the Ripper murders.

While living in the US, Chapman allegedly forced his wife Lucie down on their bed and began to strangle her, only stopping to attend to a customer who walked into the shop which adjoined their room.

Based on his expertise, review of investigation documents, and the use of geographical profiling software, he was convinced that the killer lived in the area of the murders; Chapman fit that bill accurately.