Although two officers of the Bushveldt Carbineers (BVC) were tried in connection with the murder and acquitted, there is evidence that one of these – Lieutenant Peter Handcock – afterwards confessed to the killing.
In the week before his death, Heese escorted a sick friend, Mr. Craig, to the Swiss Mission Hospital at Elim, north of Fort Edward, for an operation.
Heese was in a hurry to get back to the mission station at Makaanspoort as his fourth daughter was to celebrate her first birthday on 26 August 1901.
Heese spoke to Boer prisoners of war, some of whom he knew, including Mr. Vahmeyer, a teacher at Potgietersrust.
Heese and a young African boy named Silas proceeded by horse-buggy with a white flag attached, but both were shot dead before they reached Makaanspoort.
Heese married Johanna Grützner, the German-born daughter of a fellow missionary from the Orange Free State.