The law enforcement is always on the hunt for terrorists or big criminals. Most already have good mug-shot which can help to find a face in a crowded place such as an airport [16]. And when agents are trying to hunt some criminals down, then they will probably try to flee the country. At the airport, face recognition can be of big help. The faces of these criminals are collected and stored in a database with faces of people who are not allowed to board a plane. The faces of travelers are being scanned and are being compared with the database at the security check. If the program founds a match, the guards of the airport will go to them and cameras will be turned to the person for live images. After picking the person up, the guards will try to decide whether to keep the person from going to an airplane or they decide that it is not the face that they are searching for [27].

iii. Face recognition in photographs
To search for a specific name by only having a picture of someone, you need face recognition. Not only the society can drag a picture in the uploading square of a software or site to search through a database full of different faces with matching names, but also the police has such a kind of software. As stated earlier, it occurs often that the police state a call for help from the surrounding people. They want the people to be an extra pair of eyes to tip them off if they encounter a wanted person (for example see them across the street on the telephone), who can be in hiding or not. Society can then send in pictures of the person. Before going to hunt that specific person down, the police force needs to check if this is the person they are searching for. First, they need a picture with a clear face. The police can get a couple of those pictures and they all go through a software that tries to match the face on the picture to the wanted face. If they match, then an alarm will go off that they have found the criminal and from there on they can take action. If the result is negative, then the force will wait for more images. The effectiveness of this depends on the quality of the picture [14]. If the quality of the picture, which has a match, is high, then the chance of having a “false positive” will be smaller than a picture with low quality.

But there are some disadvantages to this method. What if the police database doe