Riddle

A famous chemist named George was found murdered in his laboratory. The police knew that two people were involved in his murder and there were 5 suspects named His Younger Brother, John, His Friends Jack and Bob, And his Son Nicolas and Son's Friend Felix and his Elder Brother Max. Police also found a note which was written by the chemist. In the note, there were written some numbers “26-3-54 / 28-27-57-16”. After reading the numbers, Police didn't understand what it was, So they called Sherlock Holmes. Sherlock Holmes immediately knew who it was and arrested them. Who did this and How did Sherlock Holmes knew who it was.