Anna Bakalis of United Teachers of Los Angeles writes a clarification:
Got this from the LASPD site: Los Angeles School Police Department (LASPD)is the largest independent school police department in the United States, with over 410 sworn police officers, 101 non-sworn school safety officers (SSO), and 34 civilian support staff dedicated to serving the Los Angeles Unified School District (LAUSD). It is the fifth largest police department in Los Angeles County, and the 14th largest in California
The NYPD officers in New York City public schools are part of the New York Police Department, not an independent school police department.
Diane Ravitch's blog 
There are NO NYC Police Officers IN NYC schools. There are 5,000 School Safety Officers (SSO), 90% of color, 70% women, many live in the neighborhood of the school, they monitor entry into school buildings, in addition SSOs conduct the scanning, the metal detectors required for entry into 90 school buildings, almost all high schools. The SSOs are supervised and trained by the PD, over the next two years the supervision and training will revert to the Department of Education.
Principals are instructed if an incident occurs in a school and requires police action to call 911- as with any other citizen
Under previous mayors, Guiliani and Bloomberg police officers were assigned to schools, that has not been the case for a number of years.
Two years ago a student in a non-scanning building fatally stabbed another student,
This is all very confusing, and I fear my posts have made the confusion worse.
I would love to find an authoritative source to clear up the trail of error.
A handful of LAUSD officers serve the District at large and provide support to the most difficult sections of its jurisdiction, but most are assigned to each secondary school cluster (a high school and its associated/affiliated middle and elementary schools). Officers are busiest after school, of course, but a fraction of them also monitor District properties throughout the night. The ratio is about one field officer for every 5000 students, splitting most of their time between the junior and senior high schools.
LAUSD officers may occasionally make a presence around elementary schools, but that’s generally to deter speeding and jaywalking.
Schools were much less safe back in the 90s, during the country’s peak period of violence. I haven’t heard gripes about police presence in LAUSD schools for years…
If you go to the LA School Police website, it says the salary range for officers is $48 to 60,000. http://www.laspd.com/recruitment.html
If you go to the LA Unified website, it says the says the salary range for school police officers is $60 to $93,000. https://achieve.lausd.net/Page/15635
In other words, it’s difficult to get accurate, verifiable information from the website(s), for many reasons.
Like LAPD officers, LAUSD police officers make about the same as a veteran teacher.
Not sure what their pensions are like, but LAPD officers get 100% after 20 years…same as firefighters.
I’d assume that a lot of LAUSD officers have retired from the police departments of neighboring municipalities but plan to work for another 10-20 years [not yet ready to retire to Idaho.]
a key point