The electromagnetic wave can trigger a suicide, which is categorized as a disguised suicide as it is actually created by the wave. It is notionally a murder, but its methodology is hard to be revealed as such.
On the other hand, there is a true disguise of the suicide, which is quite similar to a murder by the radiowave manipulation, but slightly different. For example, the electromagnetic wave is not a perfect way to kill a subject, who might be mentally resilient of the external maneuver. However, the suicide disguise takes place after the spy kills a target to cover up.
In this case, it is necessary to prepare a reason why the subject has decided to die. It might be written somewhere or told to someone that the target has had a trouble or suffering. This is assumed to be a cause of the suicide, which can make the police believe it is not an act of the murder. The truth sometimes does not matter and it is quite often that they have not pursued further if it is reasonably explained as a suicide.
The intelligence organization is a professional to disguise a scene, hence it is hard to be revealed. It might be orchestrated by the professional contractor, or might be cleaned up by the internal team. This difference depends on who decides an eliminative mission and what kind of resources they can avail at the scene.
In any way, if there is no evidence of the murder with a reasonable explanation of the suicide and if it looks like as such with the reinforced evidence and witness, the police cannot be bothered to investigate the detail.
The police itself is sometimes involved in this operation. The Japanese intelligence is a part of the police department, hence they can monitor an on-going investigation in the detail and halt it if necessary, which means their assassination cannot be prosecuted in Japan.
This disguised suicide is quite similar to the one created by the electromagnetic wave, and actually, the electromagnetic suicide is a developed from the disguised, which is why they are similar in nature.
Both of them are still conducted quite often by the spy as they believe there is a target to be eliminated. If their obstructive subject is physically gone, they can pursue their goal more easily, hence they are not hesitant to avail this methodology as the ultimate plot.