Poison, Mistaken Identity and a Sermon

In 1839, there was a mysterious death in Greenwich Park near the 'wilderness'. An unknown young man was found dead, apparently from poison. He was scruffily dressed but not impoverished, and there were no signs of violence. A loaded pistol in his pocket suggested suicide to the investigators, but there was no trace of a phial or paper which might have held the poison.
One part of the mystery was apparently cleared up when a Greenwich pensioner suggested he might know the man. Before joining the Navy, he had been in service; that very afternoon he had spent time with the son of his former employers. Sure enough, when he saw the body he was overcome with grief and positively identified it as his young friend.
However, there was a twist: the very next day, the pensioner met the 'deceased' - still very much alive and well. The identity of the corpse remained shrouded in mystery, but the manner of death was becoming clearer. The post mortem had found prussic acid in the stomach; an empty phial had also now been found near the site of the body, confirming the suicide theory.
Within a couple of days, the real identity of the deceased was established. He was one John Johnson, a 23-year-old compositor described as 'very eccentric' because he didn't associate with his colleagues, but 'remarkably steady'.
Matters might have been left to rest there, but a local preacher saw an opportunity. He quickly produced the following flyer:

SUICIDE.
THE REV. JOSEPH BELCHER,
Respectfully announces his intention of preaching a
SERMON AT BUNYAN CHAPEL SCHOOL AND LECTURE ROOM,
LEWISHAM ROAD, GREENWICH,
ON SUNDAY EVENING, SEPT. 8, 1839,
With a reference to the recent SUICIDE IN GREENWICH PARK;
In which he will communicate some awfully interesting particulars of the deceased.
THE ATTENDANCE OF THE YOUNG IS EARNESTLY SOLICITED.
Service to commence at half-past Six o’clock.

With the Reverend's promises of 'awfully interesting particulars', it is hard to fault his talent for publicity - although we might question his taste.