When comes the next bus? What is the best way to remove oil stains from clothing? One grip on the smartphone – you already have the answer. Almost everyone browses the Internet many times a day, quite naturally and sometimes almost unconsciously. And criminals are not immune from that either. The work of the investigators changes that significantly.
However, this text is not supposed to be about cybercrime, but about purely physical crimes such as theft or murder. Because the internet can play an important role here too. “There is more and more evidence in the digital world,” says Fabian Puchelt from the Bavarian State Criminal Police Office. This is also evident again and again in court cases in which virtual clues can help convict suspects.
Googling to Murder
A few examples: The fiancé of the killed Regensburg student Maria Baumer, who has meanwhile been convicted of murder, searched the Internet for the perfect murder and the fatal dose of a sedative. In another case, which was heard before the Nuremberg Regional Court, a defendant found out about fatal stab wounds on the Internet before stabbing a rival with whom he had previously arranged to meet by text message. In a trial in Trier for a series of thefts of endoscopes from clinics, two men made themselves suspicious, among other things, because they had previously searched for the affected departments on the Internet. In Hamburg, a defendant googled “Dead pensioner apartment Hamburg” after a knife attack on an old woman only five hours after the crime – with details that probably only the perpetrator could have known.
Securing cell phones and computers has become part of everyday life for the police in many crimes. For murder investigators like Frank Engelhardt from the Central Franconian Police Headquarters in Nuremberg, this is both a blessing and a curse, as he says. This often means that thousands of data have to be evaluated. “You can draw a lot of evidence from this,” he says. For example, many apps require location services so that one can see whether someone was at least in the vicinity of the crime scene. The contacts could reveal whether the victim and suspect may have known each other. Chat history and search queries could also substantiate a suspicion. Engelhardt has worked for the police for more than 30 years, 15 of them in the field of death investigations. His work has changed a lot over time. “Today the cell phone can give me the first clues. In the past, people used to ask a whole block of streets whether someone saw something. That was very tiring.”
IT forensic scientists in a race with smartphone manufacturers
The digital data can help with the investigations, but at the same time often make them more extensive and tedious – especially when several devices have to be evaluated. “The abundance of data is a challenge. It can then become a search for a needle in a haystack,” says Puchelt. The prerequisite, of course, is that the police’s IT forensic experts have access to the data at all.
The encryption software from smartphone manufacturers is a hurdle, says Chief Public Prosecutor Thomas Goger from the Cybercrime Central Office in Bamberg. If the owners of the seized smartphones do not reveal their access data or the police cannot find them noted down somewhere, the IT specialists have to try to crack them. “It’s a challenge,” said Goger. “This is, to a certain extent, a race between investigative authorities and manufacturers of smartphones, some of whom place great value on good encryption.” As a rule, according to the LKA, it is still possible to get the data. “But it takes longer,” says Puchelt.
Limits to reading along
As in an open book, the investigators cannot read the data. You are only allowed to look at those related to the crime. And the evidential value also has its limits. “The data are one of several pieces of evidence,” said Engelhardt. If a suspect searches the Internet for the price of a weapon, for example, that alone is not enough to convict him because it is not certain that he has actually bought it. Some data are also confusing and lead on the wrong track, says Engelhardt. It also happens that the accused deliberately set the wrong track. This is also confirmed by Goger: “I have already had cases where defendants have alleged that their computer was hacked. However, it is not that easy to completely eradicate its traces.”
The Erlangen computer science professor Felix Freiling has repeatedly been able to show in experiments that wrong tracks are not easy to lay. He hired master’s students to manipulate a browser history to make it look like someone had committed a crime. He finds the result very reassuring, says Freiling, who advises the Central Cybercrime Office: “In all cases, the forgeries were noticed.”