There is a perfect unsolvable murder case

Crime in Bavaria. The forensic intelligence experts are often the heroes in a criminal case.

Investigators also found the DNA trace of a man at the crime scene in the double murder of Höfen - he is now being searched for. Guido Limmer, 52, was head of forensic intelligence in Bavaria for many years. The Munich lawyer headed the Forensic Science Institute in the State Criminal Police Office from 2009 to 2016. There over 200 employees from umpteen disciplines search for the decisive clues to convict criminals. The chemists, physicists, mathematicians and engineers have already solved spectacular cases. In a new book, Limmer, who recently became Vice President of the Police Headquarters in Kempten, presents a selection - with unusually detailed insights.

-What is your case at the moment?

A murder case in Neu-Ulm, a kickboxing world champion was shot on the street, in front of his wife and child. There is still no trace of the perpetrator.

-That sounds like a crime thriller. Is there such a thing as a perfect murder in reality?

I don't think the perfect murder is planned, it happens by chance - when there is no relationship between the perpetrator and the victim and no motive. Most murderers go overboard with planning, leaving too many wrong leads. The investigators notice.

-Some killers are pretty stupid, aren't they? Your book, for example, deals with the case of a student in Passau who is murdered by two men in her apartment. One leaves the wallet lying around, the other the scrap sheet for a dry cleaner ...

Some perpetrators make it easy for you. That is why many murders are resolved within three days, simply because there are so many clues. Especially with relationship acts. But there are enough cases where we have to look for the one tiny lead.

-The investigation technique is getting better and better. Old traces of DNA suddenly become visible. You have proven a perpetrator to be murdered by playing a song on his cell phone at a certain time. Is it getting harder for perpetrators?

If you look at cell phones and computers, people leave many, many traces these days. But sometimes the amount of data is too huge to evaluate. And it is often difficult for us to access the data. Many files or chats are encrypted. First you have a huge data salad that our mathematicians have to decipher. But that's exactly what we're very good at in Bavaria.

-Are you approaching a coldly planned murder or a murder out of affect?

I am particularly concerned with cases in which children are victims of sexual abuse or murder.

-Which case shaped you particularly?

The case took place in 2004, when a young man sent ten letter bombs to local politicians, members of parliament and the Polish consul general (see below). The pressure from superiors and politicians to resolve the case quickly was enormous. But we simply had no leads, no crime scene from which one could read anything about the perpetrator.

-You were the head of the special commission. Are you still sleeping peacefully there?

At some point you have to sleep. But I often woke up long before the alarm clock went off and pondered: what else could we try? We hoped the next bomb wouldn't hurt anyone - and that we'd find a lead one day. And indeed: there was a skin flake in the fourth letter!

-Were you relieved when you knew who the perpetrator was?

Because the pressure was gone. But we would have liked to ask him why he did that. Unfortunately that was no longer possible, he had blown himself up. Of course, one asks the question: Has the pressure to investigate drove him to his death? But we just had to prevent worse.

-Why did you write the book?

During my time at the Forensic Institute, it happened that an investigator called and wanted us to carry out a certain investigation. When I pointed out that this study does not exist, he said: “But I saw that on TV!” I want to show in the book what is realistic and what is not. And I wanted to show how scientists and investigators work together.

-What discipline do you particularly like?

I don't want to highlight any. But there are cases that you remember. For example: In a small company, the boss was anonymously accused of having sexually abused female employees. An investigator has bitten into the case and had the staples on the anonymous letter examined. Every stapler leaves its own mark. And so the boss could be relieved - and an employee was transferred. Because of a staple!

-On television there are often arguments between forensics, coroners, investigators ...

This is an exaggerated antagonism. In reality, such a conflict looks more like this: A Soko leader is under pressure, wants to clarify the case quickly and submits dozens of applications for investigations to the state criminal investigation office. You then have to sit down with the investigator and ask what he really needs and advise him which investigation will lead to the fastest result and what would be a waste of time.

-Do you annoy TV crime novels?

Sometimes it does. The lone fighter, for example. I prefer it when a crime scene like the one from Münster is really exaggerated.

- Police work often seems very simple ... What do you think: How will the police investigate in the future?

We are working more and more with 3D techniques (see also Bavaria & Region). We measure the location of the incident with all the details: Where is the red car? Where is the witness? So you can play through the scene again later, when new tracks emerge. That also helps when the crime scene is gone, for example because the crime took place at the Oktoberfest and the Oktoberfest is already over. I dream that investigators can walk through such a virtual crime scene.

-When the technology is getting better and better: is it all the more stressful when a case seems unsolvable?

Clear. Some cases concern the whole police family, for example that of the murdered Italian on the Isar. We just don't know who we're looking for. My hope is that at some point we will be able to evaluate DNA traces differently. DNA tells pretty much what a person's face looks like. So far, however, the legislature has forbidden to read out the external appearance from the DNA: hair color, ancestry, eyes. It will be an exciting social discussion.

Interview: Carina Zimniok