First arrested in Fago crime

Fago is a little northern village (30-40 inhabitants), currently famous because of the murder of its mayor.

As in the movies, police has arrested the candidate of the opposition party, who has confessed to be the author. It is also said that his DNA matches with some evience found in the victim's car.

However, it is still not clear whether:

a) He really killed the mayor.
b) He acted alone.

As mere members of the audience, we understand that

a) The first suspect in the story will in a short time appear as innocent.
b) Nothing has been said about a butler yet.