Richard Allan "Ricky" Kasso Jr. (March 29, 1967 – July 7, 1984), also known as The Acid King, was an American murderer who killed his 17-year-old friend Gary Lauwers in Northport, New York on June 19, 1984. Two other teens, Jimmy Troiano and Albert Quiñones, were present at the murder, which took place in the Aztakea Woods of Northport while all four were under the influence of what they believed to be mescaline, but was most likely LSD.

The murder became sensational news in New York City and across the nation due to the alleged torture of Lauwers and supposed occult aspects of the murder. The murder took place during a period known as the "Satanic panic" when there was much public concern[2][3][4] over the effects of Satanic and occult content in heavy metal music and in role-playing games. Kasso was wearing an AC/DC T-shirt at the time of his arrest and was a fan of groups such as Black Sabbath, Judas Priest and Ozzy Osbourne.