It’s been more than a month since a Douglas County farmer and his wife were injured when a bomb exploded in their home.

The case remains unsolved, Sheriff Rick Trapp said Thursday.

Lloyd Haas Sr., 69, spent several days in Kansas University Medical Center recovering from the blast that damaged his home in the 1800 section of North 1100 Road. His wife, Karen Haas, 60, was treated and released at Lawrence Memorial Hospital.

The Haases couldn’t be reached Thursday.

The Bureau of Alcohol, Tobacco and Firearms, which joined the investigation, continues to work from Kansas City, Mo., Trapp said.

“Things have slowed considerably,” Trapp said. “I wouldn’t say it’s on the back burner, because this is a serious crime and we’re doing what we can.”