Police said Saini and his wife, Kusum, were not getting along well which forced her to move out and live with her sister, the wife of Rajan.
Saini went to Rajan’s house at 7.20am on Thursday and fired a shot at his wife and then at Rajan when he tried to intervene.
Both were rushed to a nearby hospital at Pipli, where Rajan was declared dead, and Kusum was referred to the Post Graduate Institute of Medical Education and Research, Chandigarh, in a serious condition.
Kurukshetra Superintendent of police Surinder Bhoria said a search is on for the absconding accused.