The incident happened on National Highway - 28 near Sujawalpur village under Sakra police station in the district, while the trader was identified as Santosh Sah.
Samastipur ASP Anant Kumar said "Sah, a grocery whole seller, was returning on a motorbike from Sitamarhi after collecting his dues when three armed persons on motorcycles accosted him. They shot him and escaped with the bag containing the money."
The criminals left a badly injured Sah on the road and fled. The local residents took him to the hospital and informed the police, which was now conducting raids to nab those involved in the crime.