Surender Singh (47), a former sarpanch of Panchi village in Haryana, and and his son Praveen (27) are accused of killing Sajjan Pal in Gannaur, Sonepat, in 2015.
Singh's son Harpal was shot dead by Pal's relatives in 2013, the police said.
The accused were declared proclaimed offenders in the case and carried a reward of Rs 50,000 each on their head, the police said.
Acting on a tip-off, the duo were nabbed yesterday from near Shani Mandir in Alipur.
Singh was elected the sarpanch of Panchi village the second time in 2015.