The deceased SI, identified as Baljeet Singh (56), was in-charge of the Jhajjar city police post, police sources said.
His daughter, Savita (25), had been staying with him for over a year due to her strained relationship with her in-laws, said Meham SHO Narender Pal. She had been married four years back.
Pal said that a suicide note was recovered from Baljeet's pocket in which he held Savita's in-laws responsible for him taking the extreme step.
While Baljeet died on the spot, Sarita succumbed to her injuries at PGIMS, Rohtak.