The first incident occurred at 12:18 a.m., when officers responded to reports of a fight and gunfire at 2200 Banyan Way, where officers found a 20-year-old Antioch man lying in the street with gunshot wounds.
The victim was transported to Sutter Delta Medical Center, where he was pronounced dead.
Witnesses told police that a white four-door sedan - possibly a Buick or Cadillac - pulled up to the victim as he walked down the street.
Several gunshots rang out before the victim fell to the ground. Then, two suspects fled on foot while the remaining suspects sped off in the vehicle, according to witness accounts to police.
Police responded to a second report of gunfire at 12:52 a.m., when they arrived at the 7-Eleven at 4355 Hillcrest Ave. near Wildhorse Drive.
Officers found the convenience store's 64-year-old male clerk suffering from two gunshot wounds - one round hit him in the arm and the other struck him in the hip. Police said the man is expected to survive.
A witness told police four shots were fired before four men were seen running from the store.
Less than an hour after the initial shooting, police responded to reports of a gunshot victim at Sutter Delta Medical Center, where they spoke with a 22-year-old Antioch man.
The man told police he had been shot by an unknown party on Banyan Way earlier.
The man's injuries were serious, and he was transported to a trauma center.
Police are trying to determine whether or not these incidents are all related and what motivated the shootings.
Anyone with information is asked to contact Antioch police Det. James Stenger at (925) 779-6884.