Stationed on Tarsus IV in 2246. Lieutenant Commander of Observation Outpost Tarsus IV (OT-4).
Close friends with his team, in a serious relationship with colonist Balayna Ferasini. Lost multiple team members to Kodos the Executioner's soldiers, lost Balayna in the massacre that took the lives of four thousand colonists.
Combined forces with the crew of the USS Narbonne, which arrived one day after the tragedy. Notable among its complement: Commander Philippa Georgiou.
Not above unethical interrogation. Didn't enact martial law but he will capitalize on it.
Emotionally compromised, willing to keep his phaser holstered and eliminate threats through cathartic physical combat. He struggles with ideas of violent retribution towards Kodos.
Issues just so many death threats.
And uses enemy prisoners in his search for Kodos, as guides and canaries (where the coal mine is filled with bombs).
Heads a manhunt into the mountains with the intent of bringing Kodos to justice. Unless...
Kodos resists. After a firefight in Kodos's makeshift cavern headquarters, Kodos is seemingly killed by a grenade.
The charred remains in the cave are confirmed within 99% certainty to be Adrian Kodos. In reality, Kodos was rescued by a remaining sympathizer, leading to the events of TOS episode "Conscience of the King."
A decade later, Lorca is canonically alive and imprisoned by the Terran Empire in the Mirror universe.
Since Tarsus IV, his record has been uneventful and without reproach. He switched tracks to Command, eventually becoming captain of the U.S.S. Buran.
Lorca had been contemplating retiring from Starfleet and settling down with Balayna. When she died, he put aside notions of such a life for himself, and doubled down on his career.
Would have never sacrificed the Buran crew, much less without including himself in that action, thank you very much. He operated with the ethos "We leave no one behind." (Source: Rise of Discovery, Star Trek Online)
history.