A 16-year-old pupil at a school in Rangwe sub-county on Sunday stabbed his 18-year-old brother with a kitchen knife as they were fighting over a trouser.
The Standard Seven pupil was later arrested as police carry out with investigations.
Witnesses said the victim, who worked at Asumbi Teachers Training College, was angered when he found out that his brother had worn his pair of trousers without his permission and left it dirty.
He confronted his younger sibling and a fight began.
Central Gem chief Peter Otieno said the pupil disappeared, but returned to confront his brother shortly after. He had a knife.
The younger man allegedly stabbed his brother in the stomach then took off.
The victim was taken to Rangwe sub-county hospital, but could not be attended to because doctors in Homa Bay County were on strike.
He was later transferred to Jaramogi Oginga Odinga Referral Hospital in Kisumu, where he died hours later while receiving treatment.
Residents later found the boy and tried to lynch him, but the chief rescued him and took him to Rangwe police station.