The shooting happened outside an auto parts store on Cypresswood just before 9 p.m.
Deputies say the victim and his son went there to meet some men they met online to buy something.
One of the men got out and opened fire, hitting the father multiple times.
Deputies say there was an exchange of gunfire. Later, a man showed up at a hospital with gunshot wounds.
That man may be the suspect, deputies said.
The sheriff's office cautions anyone using online sites like Craigslist should always meet sellers in public places, during daylight hours.