There is an excellent book which takes place in El Monte called "My Dark Places". It is the true story of the murder of crime writer James Ellroy's mother. I read it. Outstanding - even though I didn't grow up in El Monte.
"Crime novelist Ellroy (American Tabloid) was 10 in 1958 when his mother, a divorced nurse and closet alcoholic, was found strangled to death in a deserted schoolyard in California's San Gabriel Valley. The case was still unsolved in 1994, when Ellroy hired retired L.A. homicide detective Bill Stoner to investigate...."
from
Amazon.com: My Dark Places: James Ellroy: Books