Lake County prosecutors have amended the charges against a Polson man accused of hitting his father-in-law in the head with a hammer, causing fatal injuries.

Desmond Alan Mackay, 35, initially was charged with attempted deliberate homicide for the March 5 attack on 67-year-old John Barrows of Polson. Barrows died 10 days later at a Kalispell hospital, leading prosecutors to change the charge to deliberate homicide.

Mackay’s arraignment had been scheduled for Thursday but was postponed for a week until the state can assign him a public defender.

Mackay remains jailed.

A court affidavit says James Hoskinson told investigators he had been in a garage with Mackay when Jesse Waugh walked in, grabbed a car battery and walked outside. Hoskinson said Mackay then grabbed a hammer, called Waugh’s name and waited by the doorway.

When the door began to open, Hoskinson said Mackay quickly jerked the door open, swung the hammer and hit Barrows in the head, court records said.

Waugh told officers there had been previous problems between himself and Mackay over work and money, court records said.

Mackay told investigators he hated Waugh and meant to hit him with the hammer, court records said.