A man in Wisconsin killed his wife then blew up his house to cover up the crime, police say

Personnel go through debris the day after a home was levelled from an explosion in Madison. Photo / AP

There had been no formal reports of missing people - not from family or friends or neighbours - during the weeks, or even months, that police believe Lee Anne Pirus was dead in her Wisconsin home.

She had been shot and killed weeks ago, police said. But the 50-year-old's body was not discovered until last weekend, after the beige, two-storey home she shared with her husband went up in flames following what the authorities called a "hellacious explosion".

Investigators believe Steven Pirus blew up the home in Madison in an attempt to cover up his wife's death.

"Steven Pirus shot and killed Lee Anne," Madison Police Chief Mike Koval said at a news conference, according to ABC affiliate WKOW. "Steven intentionally blew up this house. He's as much as admitted it over the course of several days of conversations."

Koval said that evidence shows natural gas was involved in the explosion that destroyed the house last Thursday.

Steven Pirus, 59, has been arrested on charges of intentional homicide, reckless endangerment and arson. Police said the reckless-endangerment charge is because the explosion put neighbours at risk.

It was unclear today whether Pirus has a lawyer in the case.

Authorities said Steven and Lee Anne Pirus, who had been married for more than 20 years, moved in 2005 into a home on Stratton Way, in a neighbourhood near a sprawling golf course and a football park.

But in recent weeks, neighbours had not seen the woman emerge from the three-bedroom, three-bathroom house. Some told the Wisconsin State Journal that they wondered whether she might have moved.

Law enforcement officials said in a statement that firefighters responding to an explosion found the home "completely destroyed with debris spread across the vicinity. What remained of the structure was on fire, threatening nearby properties".

Neighbours were evacuated and told not to return to their homes that night.

First responders started searching the smoldering rubble for victims. On Saturday, a body was discovered "amid the debris," and soon investigators "recovered enough evidence to conclude that the explosion . . . was intentional," authorities said in a statement.

#BREAKING: #Madison Police Chief Koval says Steven Pirus faces "first-degree intentional homicide, arson and endangerment charges." #WKOW pic.twitter.com/UbzY4Xzu4c

— Ed Reams (@edreamsWKOW) September 17, 2017

"He would have had to manipulate, physically manipulate, a gas line leading from the dryer to the sub-basement in and around the area where her body was recovered," the police chief said.

The Dane County Medical Examiner said in a statement yesterday that Lee Anne Pirus was the victim. Preliminary autopsy results determined that she died from "homicidal firearm trauma and not injuries sustained in the explosion and subsequent fire," it said. Officials, however, did not release the number of gunshot wounds or say where on Pirus's body they were found.

The circumstances surrounding Lee Anne Pirus's death are uncertain. But the police chief acknowledged it was "unusual" no one seemed to question why she was gone.

Koval, the police chief, told WKOW today that police are searching for answers - "how was she killed, what was the means; and now, we're looking obviously in the thicker layers of what prompted this reaction: Was it money? Was it extramarital affairs? What exactly was there going on in the dynamics of this couple?

"He's probably going to allege that his wife asked him to do what she couldn't do for herself. But obviously, we're trying to nail it down and say, 'That's ridiculous because there's nothing to suggest that she wanted to take her life.' "