“Police were negotiating. There ... had been talking to him for several hours,” the commander told reporters.
Wilde said the suspect and his alleged victim had worked together for several years.
“Obviously it’s a tragic outcome for everyone involved,” he said.
The homicide squad is investigating the older man’s death.
Shire of Kellerberrin chief executive Raymond Griffiths said both men were local residents and the community of about 950 people was devastated by the events.
“Kellerberrin is a tight-knit community ... We are all in shock,” Griffiths said in a statement. “Our focus in the coming days will be providing any support the families that have been impacted might need.”
Griffiths thanked police for their “quick response” and asked for the privacy of the victim’s family and the community to be respected.