CORALVILLE — Coralville police are investigating shots fired in the same block where a man was fatally shot last month.Coralville Police Chief Shane Kron said officers were called to the 900 block of Boston Way at 6:23 a.m. Sunday for a report of four shots fired. Kron said officers found three spent shell casings.“No one was injured, and the specific target was undetermined,” Kron said Monday.The incident took place a month after a Christmas night shooting that left Gregory Jackson, 30, of Iowa City dead and three others injured.