Sadly, he was pronounced dead at the scene.
A teenager who was also present at the address was taken to hospital for treatment for minor injuries.
A local man remains in custody, having been arrested on suspicion of murder.
Speaking to the local community, District Commander, Chief Inspector Jon Evans, said: “I’d like to reassure the local community that we are treating this as a targeted, isolated incident.
“Since our appeal this morning, we’ve had locals send us CCTV and doorbell footage, as well as talking us through anything they may have seen or heard late last night or early this morning.
“Greenstead is a tight-knit community. We know that the answers to this crime will lie somewhere within it – whether that’s in CCTV or dashcam footage, something you’ve heard, or something you’ve witnessed.
“If you think you have relevant information and you haven’t reached out to us yet, you can call us on 101 or submit information or footage straight through to our Major Crime team on firstname.lastname@example.org.
“If you have information but want to remain 100% anonymous you can call Crimestoppers in complete confidence on 0800 555 111.”