April 20 is the 110th day of the year (111th in leap years). There are 255 days remaining.
- 1846 — Jonathan Balls died.
- 1936 — André Pauletto is born.
- 1944 — Robert Howard is born.
- 1963 — Anatoly Sedykh is born.
- 1965 — Richard Brad Ross is born.
- 1965 — Abron Scott is born.
- 1973 — Clarnell Strandberg is murdered by Ed Kemper.
- 1973 — Lynda Gough is murdered by Fred and Rose West (c.).
- 1977 — Karen Nills, Robert Nills and Sandra Harris are murdered by Ted Carr.
- 1977 — Ted Carr died.
- 1984 — Gary Ridgway's victim, Tina Marie Thompson, is found.
- 1984 — Julie Ann Connell is murdered by Robert Boyd Rhoades.
- 1986 — Richard Louis Hunter is apprehended.
- 1986 — Cynthia Jocelyn Zarzycki is murdered by Arthur Ream.
- 1988 — Igor Suprunyuk is born.
- 1989 — Edwin Mata Madrigal and Marta Miriam Navarro Carpio are murdered by "El Psicópata".
- 1993 — Willy Van Coppernolle is apprehended.
- 1996 — Khalil Wheeler-Weaver is born.
- 1997 — Laura Smither's victim, William Reece, is found.
- 2004 — Abdullah Shah died.
- 2019 — Harold Bell died.
- 2023 — Denis Zubov died.