After Maddie McCann case, Germany crime show helps to arrest suspect in 1988 murder case

A 56-year-old man was arrested in Cologne on Tuesday morning in connection with the suspected murder of a young woman during Carnival festivities in the city's historic old town (Altstadt), 35 years to the day after the alleged crime, police said. 

"He is accused of fatally strangling the then-24-year-old woman in the Altstadt during the night heading into Carnival Sunday in February, 1988," police said in a statement.

The breakthrough comes a few weeks after the case was again aired on a regular, long-running serious crimes TV show in Germany called Aktenzeichen XY ... ungelost (Case number XY ... unsolved). 

"Investigators were put onto the suspect's trail thanks to a witness report during the crime show Aktenzeichen XY in December 2022," police said. 

The case had been reopened in 2022, after special investigators in a cold case unit in the state's serious crimes police force (LKA) conducted new DNA analysis and started canvassing for information. This prompted investigators to put what they call the "Petra Nohl" murder back onto the TV show.

"The combination of DNA analysis by the LKA, the investigative work of the Cologne criminal police department, and the information provided after the program led to the 56-year-old man being treated as a formal suspect," police said. 

A press conference to provide further information on the case was scheduled for Tuesday afternoon. 

Cold case show best known internationally for Maddie McCann case

Aktenzeichen XY airs once a month on public broadcaster ZDF, and has been running since 1967. 

According to data published by ZDF at the end of 2022, the show had tackled 4,952 different cases — with 1,948 of them having since been solved. ZDF called this success rate in the region of 40% "a proud figure because often it's the 'hopeless' cases which wind up on XY — cases, in which police have already exhausted all the traditional methods of investigation and can only really build on the help provided by the television audience."

The show has also contributed to some other recent investigative breakthroughs in Germany. The arrest in January of a German man in an Italian hotel, suspected of a fatal shooting in Nuremberg in October, followed an airing of the case on the show and subsequent calls from viewers. 

A 41-year-old man accused of causing an explosion on a ghost train in Duren, was apprehended in November, with police crediting tips from the show as contributing to detaining the suspect. At the time of his arrest, he was suspected of a similar crime in Düsseldorf but those investigations were ongoing. 

But the most famous international case where the show hopes to play a role in bringing about closure is the disappearance of Madeleine McCann in Portugal in 2007. The German man suspected in connection with her disappearance, currently serving a separate prison sentence for a rape committed in Portugal in 2005, was identified in part because of the case featuring on the show.

McCann's parents appeared on the show in person in 2013, and even then calls came in from viewers pointing towards the current suspect, only at that time there was insufficient evidence for prosecutors to act. Police received more information from the public after showing some of their latest clues to viewers in 2020, followed soon after by the man being formally identified as a suspect in what German police suspect will prove to be a homicide case. Officially, McCann remains a missing person since disappearing aged 3.

Aktenzeichen XY is also credited as the inspiration for shows like "Crimewatch" in the UK or "America's Most Wanted" or "Unsolved Mysteries" in the US.