Captain Boomerang (Owen Mercer) is the son of the original Captain Boomerang, George "Digger" Harkness, and also took up his father's mantle shortly before the Infinite Crisis.
Owen was born to George Harkness and Meloni Thawne-Allen when Harkness was briefly trapped in the 30th Century.
When Harkness found himself an obsolete villain in the modern world of super-villains, he felt it was finally time to reach out to the son he never raised, who had somehow managed to follow him to the 20th Century, and the two bonded. Taking up his father's legacy, Owen became the second Captain Boomerang. Captain Cold, brother to Golden Glider (who was believed to be Owen's mother), took Owen in as one of the Rogues.
- Captain Boomerang can be found in the Hall of Doom selling high tech gear.
- Owen Mercer first appeared in Identity Crisis # 3 (October 2004).
- Owen's biological mother, Meloni Thawne-Allen, is also the mother of Kid Flash.
|Heroes||Arsenal - Batgirl - Batman - Black Lightning - Fire - Geo-Force - Grace Choi - Green Arrow - Huntress - Metamorpho - Nightwing - Starfire|
|Villains||The Brain - Brother Blood - Deathstroke - Felix Faust - Gizmo - Gorilla Grodd - Jinx - Mammoth - Manhunters - Monsieur Mallah - Psimon - Doctor Sivana|
|Other||Captain Boomerang (Owen Mercer) - Catwoman - Martian Manhunter - Phantom Stranger|
|Bunker - Penthouse - Dive|
|Weapons||Dual Pistol - Exobyte-Infused Escrima Sticks - Katana|
|Apparel||Dark Specter Batsuit - High Voltage|
|Stagg Enterprises Gotham HQ|
|Checkmate - Church of Blood - Fearsome Five - Justice League of America - OMAC - Stagg Enterprises - Suicide Squad - Teen Titans|
|Affiliates||Amanda Waller - Bane - Black Adam - Captain Boomerang (George Harkness) - Captain Boomerang (Owen Mercer) - Captain Cold - Deadshot - Doctor Light - Duchess - Harley Quinn - Killer Frost - King Shark - Mirror Master - Oracle - Parasite - Penguin - Poison Ivy - Power Girl - Solomon Grundy - Speedy - Steel - Superboy - Vixen|
|Adversaries||Batman - Lois Lane|
|Other||Chemo - Vicki Vale|
|Bombshell Belle Reve's Poster|
|Apparel||Expert Marksman - Punchline|
|Belle Reve Federal Penitentiary|
|PvP||Belle Reve Sanitarium|
|Checkmate - United States of America - Justice League of America - Justice Society of America|