A man went berserk, killing his parents and a neighbour in Siritanyi village, Bungoma county, before angry locals lynched him on Tuesday.
Yusuf Seyunda, 25, first attacked his mother Grace Akot at their Kanduyi home with a club, killing her instantly.
Police said the man then killed Joseph Masafu, a neighbour who responded to Akot's distress call.
After this, Yusuf went to the family's farm which his father was weeding, and killed him.
Villagers who gathered beat him to death at St Wycliffe Church where he had sought refuge.
Daniel Wabwile, a witness, said the incident happened at around 6pm, immediately after heavy rains pounded the area.
"Seyunda seemed high on some substance. He had a club in his hand and was attacking people haphazardly. We were forced to scamper for safety," he said
He described the man as "a very reserved person who had just graduated with a diploma in agriculture from a Bungoma college".
Julia Nasimiyu, who lost her husband during the fight, told the Star that she had, for many years, known Seyunda to be a polite person.
"He threatened to kill me or anybody else who moved near him."
Residents blamed police, saying their laxity has worsened drug abuse in the area.
Area DCIO Bernard Chepkwony said: "It is suspected that he was using drugs because there was no family dispute."
The bodies were taken to the Bungoma Referral Hospital mortuary.