Mr. & Mrs. Smithers are Darryl's parents. They only appear in one scene in Lethal Weapon 3.
Lethal Weapon 3
Mr. and Mrs. Smithers are present at their son's funeral. Possible aunts, uncles, siblings and cousins of Darryl's are also in attendance.
It is an emotional moment for the couple and LAPD Sergeant Roger Murtaugh, who shot Darryl in the gunfight a few days earlier, comes and tries to apologize to both the parents for killing him. Mrs. Smithers, however, slaps Murtaugh in the face as she continues crying into her husband's shoulder. Mr. Smithers, however, advises Murtaugh to find the man who sold the gun to his son, just before they left in order to atone for the killing.