"Two cops. Glover carries a weapon..Gibson is one. He's the only L.A. cop registered as a 'Lethal Weapon'".
The original Lethal Weapon movie was released in 1987. There were a number of sequels, including Lethal Weapon 2 (1989), Lethal Weapon 3 (1992), and Lethal Weapon 4 (1998). All of them starred the main characters of Mel Gibson as Martin Riggs and Danny Glover as Roger Murtaugh. Focusing on the first movie, reviews were mostly positive, and the film was a huge success at the box office.
In the original movie, homicide Detective Murtaugh is close to retirement. He decides to try to solve one last case before calling it quits, that being the murder of his friend's daughter. Murtaugh discovers that his friend's daughter had been involved in a heroin smuggling operation, and since drugs were involved, Murtaugh was required to partner with a a psychotic narcotics officer named Martin Riggs. They soon discover that the drug ring is a major operation, headed by retired General McAllister and his lead henchman, Mr. Joshua (played by Gary Busey).
The sequels were variations of the same buddy-cop theme. The second movie, for example, had the duo protecting Leo Getz (Joe Pesci), a nark mixed up in an African human trafficking and drug operation. The second movie was also a huge box office draw, although it did not fair as well with critics as the original. The final two movies were also considered financially successful, even though they did not earn as much as their predecessors.