April 4 is the 94th day of the year (95th in leap years). There are 271 days remaining.
- 1836 — Sophie Ursinus died.
- 1942 — Michel Fourniret is born.
- 1943 — Judy Buenoano is born.
- 1943 — Ronald Turney Williams is born.
- 1946 — Marcel Petiot received the death penalty.
- 1961 — Bill Currier (Victim) is born.
- 1973 — Margaret Hittle and Henry Hittle are murdered by Daniel Hittle.
- 1974 — Kevin Bright is attacked by Dennis Rader.
- 1974 — Kathryn Bright is murdered by Dennis Rader.
- 1978 — William Henry Hance is apprehended.
- 1979 — Josephine Whittaker is murdered by Peter Sutcliffe.
- 1980 — Steven John Wood is murdered by William Bonin.
- 1981 — Bruce Lindahl's victim, Charles Robert Huber Jr., is found.
- 1981 — Bruce Lindahl died.
- 1987 — Umberto Zadnich is apprehended.
- 1989 — Lin Zongcheng, Lin Benjian, Hong Minxiong and Wen Jinlong are executed by firing squad.
- 1990 — Genevieve Zitricki is murdered by Robert Brashers.
- 1999 — Debra Harris and Ambria Halliburton are murdered by Tommy Lynn Sells.
- 1991 — Lee Choon-jae's victim, Kwon Soo-sang, is found.
- 1997 — Jacqueline Weiss is murdered by Émile Louis.
- 2001 — Ramon Hernandez is apprehended.
- 2022 — Roula Pispirigou is apprehended.
- 2022 — Martin Lee Sanders died.