a few police, not many police, a few police officers, etc
The noun police is unusual. Police is usually treated as plural, and has no singular form, except maybe a 'police officer', or a policeman.
The word originated from the word tadpole. As a tadpole is small. And the meaning for the word tad is small or a small amount.
A pinch
smidget
small
iota
Pinch, trace
Measure.
Jot
Titch is British slang for a small amount.
A moment, a second, an instant.
trace
This corpse has suffered no small amount of decomposition.