May 18 is the 138th day of the year (139th in leap years). There are 227 days remaining.
- 1815 — Adelheid Gottfried is murdered by Gesche Gottfried.
- 1871 — Edward H. Rulloff died.
- 1921 — Emil Schutte is apprehended.
- 1927 — Harvey Carignan is born.
- 1935 — Milka Pavlović died.
- 1938 — Samuel Evans is born.
- 1946 — Bill Bradford is born.
- 1960 — Sue Curtis (victim) is born.
- 1971 — Wayne Boden's victim, Elizabeth Anne Porteous, is found.
- 1977 — Montie Rissell is apprehended.
- 1979 — Yegor Khabarov is born.
- 1980 — Eric Middlebrooks is allegedly murdered by Wayne Williams (suspected victim).
- 1980 — William Bonin's victim, Lawrence Sharp is found.
- 1981 — Laron Williams is apprehended.
- 1983 — Richard Bruce is murdered by Larry Eyler.
- 1986 — Anne Lock is murdered by John Duffy and David Mulcahy.
- 1986 — Michael Lupo is apprehended.
- 1991 — Eugene Broxton is apprehended.
- 1994 — Albert Morris is murdered by Gary Ray Bowles.
- 2000 — Sanjay Sharma is apprehended.
- 2005 — Vernon Brown died.
- 2023 — Lao Rongzhi died.
- 2024 — Agustín Ramón Martínez died.