A man allegedly killed his wife and three-year-old child over a family feud at Char Gopalpur village in Gunaritala union under Madarganj upazila of Jamalpur early Wednesday.
The deceased were identified as Shikha and her son Taufique, hailing from the area.
Police arrested the suspected killer Harun-or-Rashid, son of Fazlu Member from the same area.
Gunaritala union parishad member Akber Ali, said Harun had an altercation with his wife. At one stage, Harun started beating Shikha and child Taufique with a stick, leaving them dead on the spot.
Rafiqul Islam, officer-in-charge of Madarganj Police Station, confirmed the matter. Process of filing case was underway.