May 12 is the 132nd day of the year (133rd in leap years). There are 233 days remaining.
- 1897 — Earle Nelson is born.
- 1944 — John Edward Swindler is born.
- 1961 — Isabel Cristina Torreão Pires da Silveira is born.
- 1971 — Clinton Bankston is born.
- 1974 — Tony Costa died.
- 1979 — Billy Lee Chadd is sentenced to Death.
- 1980 — Alexander Hernandez is born.
- 1981 — Dzung Ngoc Tu is murdered by Michael Ross.
- 1983 — James Koedatich is apprehended.
- 1986 — Lisa Strong is allegedly murdered by Paul Rhoades (suspected victim).
- 1992 — Sherry Palmer is allegedly murdered by Robert Lee Yates (suspected victim).
- 1997 — Dimitris Vakrinos died.
- 1998 — Melody Ann Murfin is murdered by Robert Lee Yates.
- 2011 — Matej Čurko died.
- 2015 — William MacDonald died.
- 2018 — Dennis Nilsen died.