Police have arrested 39-year-old John Cahan on suspicion of assault with a deadly weapon and elder abuse. His father, whose name was not released, was in critical condition Monday night at Sharp Memorial Hospital.
City News Service reports that Cahan allegedly barged into his father's bedroom in San Diego County's Spring Valley and roused him from sleep early Sunday.
Sheriff's Sgt. Mark Varnau says Cahan angrily demanded that his father hold out a hand so he could cut it off.
He says that after swinging the sword several times, Cahan critically wounded his father's leg.