- "In Hong Kong, you would be dead."
- ―Wah Sing Ku
Wah Sing Ku is the main antagonist in Lethal Weapon 4. He was the right-hand man, main enforcer and the highest-ranking negotiator of the Triad kingpin Uncle Benny Chan, who has enslaved many Chinese immigrants and brought them to the United States on a large boat.
Wah Sing Ku is a high-ranking Chinese Triad negotiator trying to get the Four Fathers (one of whom is his older brother, Michael Sing Ku) brought out of prison and into the United States. He is a master of martial arts and even possesses the skills to take a gun away from his opponents and take them apart in one deft move, as seen in his first confrontation with Martin Riggs and Roger Murtaugh. Ku speaks Chinese as well as English, though only to his Triad members.
Ku is first seen with his henchman Fan at Uncle Benny's Restaurant listening to Uncle Benny Chan talk to a States Department man about bringing the Four Chinese Fathers into America when they receive news that the Chinese ship that was bringing a family called the Hongs to them had been impounded by LAPD Detectives Martin Riggs and Roger Murtaugh. Ku asks about the Hong family and it is revealed that they have escaped, leading Ku to order Uncle Benny to find them. Ku and some of his henchmen follow the States Department Man in their car and ram his vehicle onto a level crossing, causing it to be hit by a speeding train and killing him.
The next day, Ku talks to Uncle Benny about delivering the family and that the family's uncle, who is being forced to work for Ku, won't finish his job (which is unknown) until he sees the family. Uncle Benny tells Ku not to worry and that the family will show up, to which Ku tells Uncle Benny that in Hong Kong he would already be dead. Riggs, Murtaugh and their new partner Lee Butters enter the room and ask Uncle Benny if he knows anything about the ship that they impounded the night before. Benny lies and Riggs sees Ku nearby, looking incredibly irritated. Riggs asks Benny who he is, but Benny replies that Ku doesn't speak English before telling the cops to leave. Before they depart, Riggs tells Benny and Ku that they are onto them, while Ku silently claims "In Hong Kong, you would be dead", proving that he does in fact speak English, and that Benny lied. Once outside, Riggs, Murtaugh, and Butters find the Chinese captain of the ship and attempt to catch him, but he manages to escape. As the captain climbs onto a rooftop and believes he's home free, Ku suddenly appears and attacks him for his incompetence, foul up, and betrayal the previous night, and telling the story of their plan to the cops. Despite the captain's effort and attempt to fight back, Ku easily gains the upper hand and strangles him to death with his ligature, while holding a bead necklace all along.
It is soon revealed that the Hong family was found by Murtaugh on the night of the crash and that he is secretly keeping them in his house until they are granted an asylum, and the oldest member of the family, Mr. Hong, is in fact the nephew of the uncle working for Ku. Mr. Hong had been writing messages to his uncle and when Ku receives it, he and his men go to Murtaugh's house and kidnaps the Hongs. Ku, Chu, Fan and two other antagonists then takes Lorna, Trish, and Rianne and holds them hostage until Murtaugh and Riggs return home. Lorna manages to get free and she, Riggs, and Murtaugh take on Ku's men while Trish and Rianne try to run to safety. Ku easily beats them all and has the entire group tied up with ductape before setting the house on fire. After Ku leaves, one of the Hong children, Ping, who hid and managed to avoid being captured, cuts Riggs and the others loose and they all escape unharmed.
Ku then travels to the prison where the Four Fathers are located and promises the general that he will have the money for their release soon. He is also reunited with his older brother Michael and promises to free him soon before leaving. Meanwhile, Riggs, Murtaugh and Butters go to confront Uncle Benny at the dentist's office, while Leo distracts the dentist. They give Uncle Benny laughing gas to make him tell the truth, and Benny foolishly tells them about the plan to buying back the Four Fathers and claims that by tonight it would be too late anyways. The Hongs are taken to Ku's hideout and Chu takes Mr. Hong to see his uncle. As Hong wonders what is going on, Ku tells him that his uncle is working for him in order to pay for him and his family to come to America. When the uncle says that he will only finish his job once his family has been taken to their new home, an angry Ku chokes Hong and breaks his neck, killing him in the process as an example and threatens to kill the rest of the family if the uncle does not continue his work. Ku also kills Uncle Benny with his ligature for revealing the information about them and their hideout and the Hongs to the cops. Even after Hong's uncle did the job, Ku ended up killing him so he wouldn't reveal the information of what went on there to the cops, and because he had outlived his usefulness.
It becomes apparent that Ku had Hong's uncle make counterfeit Chinese money in order to get the Four Fathers out of prison, and before he can present it to the general, Riggs, Murtaugh, Butters, Ng, Ng's partner, and several other detectives arrive and reveal that the money is counterfeit. A fight breaks out in which the general and his men kills three of the Four Fathers, with the exception of Michael. The two are about to escape, only for confrontation from the private army members. Ku fights off the members, knocking two out with AKM and killing one by snapping his neck. During the shootout, Riggs uses a cranehold to ram Ku, who combinates martial techniques to beat Riggs. Murtaugh aims for Ku while he beats Riggs, but Ku dodges the speeding bullet, accidentally hitting Michael. Ku takes his brother near the pier and lays him down on the ground, watching sadly as he dies. Enraged by this, Ku challenges and fights both Riggs and Murtaugh and almost ends up killing Riggs choking him, but Murtaugh impales him through the back with a sharp metal stick before he knocks Murtaugh out cold. Despite the intense pain, Ku continues struggling and fighting with Riggs and they both end up falling into the river nearby. The struggle continues beneath the surface and Ku attempts to strangle Riggs, but he notices a submerged AK-47 machine-gun lying nearby and grabs it. Before Ku can do anything else, Riggs pulls the trigger and pumps Ku's body full of bullets, killing him. Riggs then swims back up to the surface, leaving Ku's corpse underwater, just before Riggs is back underwater again and pinned under a broken piece of the pier and Murtaugh dives in to save him.
Wah Sing Ku is extremely brutal, ruthless and manipulative, able to murder with techniques and major brutality without hesitation, and with no remorse or pity. He displays this by strangling both Uncle Benny and the Captain. Another example, he threatens to murder the rest of the Hong family in order to get cooperation. His manipulation is shown when he feigns surrender for Riggs and Murtaugh, then disassembles Riggs' Beretta 92FS with ease before beating them unconscious.
He is highly skilled in martial arts, and able to take down his enemy during hand-to-hand combat, as he easily does this to Riggs. He is capable of fighting efficiently, even with one hand only, while holding some object (a bead necklace) with his other hand, without decreasing his prowess even slightly. Despite this, at the end of the film, Riggs and Murtaugh manages to perform several blows onto him, proving that Ku is barely easy in combat.
Ku, on the other hand, is not entirely devoid of human emotions: he shows great care and heart-fullness towards only his older brother, Michael. This is shown during the shootout, where Ku protects Michael, such as defeating Private Agents who attack him and cradling over his dead body after he was accidentally killed by Murtaugh.
Ku is fluent with the English language, but he rarely uses it. Despite this, he remarks, "In Hong Kong, you would be dead." on Riggs in English quietly when he departs.
- Wah Sing Ku is described as the hardest antagonist by fans, due to his vicious techniques in martial arts as he manages to overpower and incapacitate Riggs and Murtaugh several times with ease.
To view the Wah Sing Ku gallery, click here.