Question: How did the subject of the 2015 Austrian thriller film "Jack" die?

Context paragraphs:
Bad Luck (2015 film): Bad Luck is a 2015 Austrian tragic-comic film directed by Thomas Woschitz.  It debuted at the 36.  Filmfestival Max Ophüls Preis 2015.

2015 Red Bull Ring GP2 and GP3 Series rounds: The 2015 Red Bull Ring GP2 and GP3 Series rounds was a pair of motor races held on 20 and 21 June 2015 at the Red Bull Ring in Austria as part of the GP2 Series and GP3 Series.  It is the first round of the 2015 GP2 season and 2015 GP3 season.  The race weekend supported the 2015 Austrian Grand Prix.

Jack Unterweger: Johann "Jack" Unterweger (16 August 195029 June 1994) was an Austrian serial killer who murdered prostitutes in several countries.  First convicted of a 1974 murder, he was released in 1990 as an example of rehabilitation.  He became a journalist and minor celebrity, but within months started killing again.  He committed suicide following a conviction for several murders.  Austrian psychiatrist Dr. Reinhard Haller diagnosed him with narcissistic personality disorder in 1994.

Hannah (1997 film): Hannah is a 1997 Austrian thriller film directed by Reinhard Schwabenitzky.  The film was selected as the Austrian entry for the Best Foreign Language Film at the 69th Academy Awards, but was not accepted as a nominee.

Play the Game (2015 film): Play The Game!  is a 2015 Austrian mystery thriller film portraying a series of events which take place in the context of a real-life game.  It was written and directed by Jörg Helbig.  The film uses elements of film noir and psychological thriller.  It opened in Austria on June 16, 2015.

MindGamers: MindGamers is a 2015 Austrian science fiction film directed by Andrew Goth.  The film was theatrically released on March 28, 2017 through Terra Mater Factual Studios.  The film stars Tom Payne, Dominique Tipper, Sam Neill, Melia Kreiling, Antonia Campbell-Hughes, and Oliver Stark.

Jack (2015 film): Jack is a 2015 Austrian thriller film about serial killer Jack Unterweger, directed by Elisabeth Scharang.  It was screened in the Contemporary World Cinema section of the 2015 Toronto International Film Festival.

2015 Austrian Grand Prix: The 2015 Austrian Grand Prix (formally known as the Formula 1 Großer Preis von Österreich 2015) was a Formula One motor race held on 21 June 2015 at the Red Bull Ring in Spielberg, Austria.  The race was the eighth round of the 2015 season, and marked the 29th running of the Austrian Grand Prix.

Revanche (film): Revanche is a 2008 Austrian thriller film written and directed by Götz Spielmann.  It centers on the ill-fated love story between a Viennese ex-con and a Ukrainian prostitute who get involved in a bank robbery.

The Last Summer of the Rich: The Last Summer of the Rich (German: Der letzte Sommer der Reichen ) is a 2015 Austrian drama film directed by Peter Kern.  It was screened in the Panorama section of the 65th Berlin International Film Festival.

Supporting paragraphs: Jack (2015 film) Jack Unterweger
Answer: He committed suicide