Lucsly was a member of the Department of Temporal Investigations in the 24th century. In 2373, along with his partner, Dulmur, he visited station Deep Space 9 to debrief Benjamin Sisko on a recent time travel incident, wherein Klingon spy Arne Darvin utilized the Orb of Time to take the USS Defiant back in time to 2268 in an attempt to assassinate James T. Kirk.
Lucsly appeared to be humorless, as did Dulmur; indeed, both said they hated jokes.
Following the debriefing, he reserved the right to comment on whether Sisko would receive a letter of reprimand for his brief encounter with Kirk wherein Sisko expressed his admiration to the man. (DS9: "Trials and Tribble-ations")
The novel The Needs of the Many gives Lucsly's first name as Adam.
The novel Watching the Clock gives Lucsly's first name as Gariff.
In Forgotten History, a novel featuring various flashbacks to the origins of the DTI, Lucsly is briefly forced to work with Kirk to deactivate a Timeship prototype from Kirk's era that has become trapped between two different eras, developing a respect for Kirk as he acknowledges Kirk's awareness of the dangers of time travel, even as he continues to publicly 'denounce' Kirk as a renegade to serve as a reminder of the dangers of time travel.
The game Star Trek Online gives his full name as "Gariff Adam Lucsly".