Following a tip from a concerned citizen reporting a suspicious man in their neighborhood on Friday afternoon, police located and interviewed the man.
The interviews led to the man's arrest for alleged murder in connection with the body found at an apartment complex in the 3400 block of Hudson Court on Friday morning, according to police.
He was taken to county jail in Martinez.
Police have not released the suspect's name.
Officers responded to a report of a possible dead body at the complex around 8 a.m. Friday.
The man, who has been identified only as a 22-year-old Antioch resident, appeared to have been shot to death and was pronounced dead at the scene, police said.
Police said the body was found on the side of the apartment complex and appeared to have been there for several hours. His identification is being withheld pending the notification of relatives.