When John Zeärtö would write: Johnny Riler Accident. Tomorrow Johnny Riler will receive a piece from the death note. He writes the true name from the person who uses the alias Xavier. Would that work? (And yes Johnny knows the true name)
This scenario is totally possible. As long the 2 main factors can be reached.
This note will not take effect unless the writer has the person's face in their mind when writing his/her name. Therefore, people sharing the same name will not be affected.
The conditions for death will not be realized unless it is physically possible for that human or it is reasonably assumed to be carried out by that human.
So if he knows the real name, and can bring the face of the person to mind. And it is physically possible for that person to obtain a piece of death note and write in it. Then yes it is possible indeed.
Whether the cause of the individual's death is either a suicide or accident. If the death leads to the death of more than the intended, the person will simply die of a heart attack. This is to ensure that other lives are not influenced.
I'm sorry but I don't think Dimitri is correct. This appears to be the same as telling L's bodyguards to shoot L. This does not work. There are quite a bit more than just those two rules.