The United States Department of Justice has announced the man suspected of making the bomb which blew up Pan Am flight 103 is in US custody.

The act of terror occurred on December 21 1988 over Lockerbie in Scotland, killing 270 people.

Deakin University terrorism expert Greg Barton told 6PR Mornings host Gary Adshead the exact details of what happened are still unknown.

“What’s not clear is the motive,” said Mr Barton.

Press PLAY to hear what Mr Barton had to say

“It was one of those turning points for aviation security,” he continued.