Who was the Killer ?

Who was the Killer ?

A certain Rich man called Bill Richman was killed. Mc Donald, apolice agent was appointed to the case. At the crime scene, there lay the the dead body and a small note that mr.Richman wrote before his death. The note read;

"1st of January, 4th of October, 5th of March, and 3rd of June"

However, Mc Donald knew that somehow, the killer's name was hidden in the note.
Below were the suspects.

Jack Richman: The son and heir of the deceased.
John Richman: The employee of the deceased
Jane Richman: The wife of the deceased.

Now. Suppose u are Mc Donald, who was the killer?

Click here for Answer

John Richman is the Killer.
The Clue is
1st of Jan : J
4th of Oct : O
5th of Mar : H
3rd of Jun : N
So John is the Killer.