The homeowner shot Nathaniel Joseph Rosa, 31, multiple times after, he said, he noticed signs of forced entry at his home in Mason County, Washington, the county sheriff's office said Saturday.
The homeowner, who has not been identified, was arrested on second-degree murder charges, the office said.
The sheriff's office announced the arrest via Twitter and said it would release more information in a press release Monday.
"There is more to the story that can not be released yet," the office said in a Twitter post Saturday.
The homeowner said he arrived at the home, one of at least two that he owns in the Belfair, Washington, area, around 8 a.m. and noticed that a door had been kicked in, according to police.
The homeowner went inside and exchanged words with Rosa, who was in the shower at the time, police said. The homeowner left the premises without calling the police and returned with a firearm, police said.
"He returned home, retrieved a firearm, came back over to the residence and fired multiple rounds into the shower ... killing the intruder," Mason County Sheriff's Lt. Travis Adams told ABC affiliate KOMO.
It's not clear how long the victim had been inside the property, but police said the homeowner had enough time to call for help before firing shots.
"Certainly he had an opportunity to call law enforcement at that time," Adams said. "And we've contacted our local prosecutor, explained the circumstances to him, and he agrees that second-degree murder was an appropriate charge in this case."