Sublime song; april 29th 1992--what's it mean by "And screamin 187 on a mother ****** cop."?

I dont know if you can,
But can you get an owner for ons,
Thats o-n-s,junior market,
The address is 1934 east aneheim,
All the windows are busted out,
And its like a free-for-all in here
And uh the owner shouldat least come
Down here and see if he can secure his business,
If he wants to...

April 26th, 1992,
There was a riot on the streets,
Tell me where were you?
You were sittin home watchin your tv,
While I was paticipatin in some anarchy.

First spot we hit it was my liqour store.
I finally got all that alcohol I cant afford.
With red lights flashin time to retire,
And then we turned that liquor store into a structure fire.

Next stop we hit it was the music shop,
It only took one brick to make that window drop.
Finally we got our own p.a.
Where do you think I got this guitar that youre hearing today?
Hey!

(call fire, respond mobil station.
Alamidos in anahiem,
Its uhh flamin up good.
10-4 alamidos in anaheim)

Never doin no time

When we returned to the pad to unload everything,
It dawned on me that I need new home furnishings.
So once again we filled the van until it was full,
Since that day my livin rooms been more comfortable.

Cause everybody in the hood has had it up to here,
Its getting harder and harder and harder each and every year.

Some kids went in a store with thier mother,
I saw her when she came out she was gettin some pampers.

They said it was for the black man,
They said it was for the mexican,
And not for the white man.

But if you look at the streets it wasnt about rodney king,
Its bout this ****** up situation and these ****** up police.
Its about coming up and staying on top
And screamin 187 on a mother ****** cop.
Its not written on the paper its on the wall.
National guard? ? !
Smoke from all around,

Bo! bo! bo!

(units, units be advised there is an attempt 211 to arrest now at 938 temple,
938 temple... 30 subjects with bags.. tryin to get inside the cbs house)

(as long as Im alive, imma live illegal)

Let it burn, wanna let it burn,
Wanna let it burn, wanna wanna let it burn

(Im feelin sad and blue)

Riots on the streets of miami,
Oh, riots on the streets of chicago,
Oh, on the streets of long beach,
Mmm, and san francisco (boise idaho),
Riots on the streets of kansas city
(salt lake, hunnington beach, ca),
Tuscalusa alabama (arcada compton mischigan),
Cleveland ohio,
Fountain valley (texas, barstow - lets do this every year),
Paramount, victorville (twice a year),
Eugene or, eureka ca (let it burn, let it burn),
Hesperia (oh, ya let it burn, wontcha wontcha let it burn),
Santa barbara, nevada, (let it burn)
Phoenix arizona,
San diego, lakeland florida, (let it burn)
******... 29 palms (wontcha let it burn)

Any units assist 334 willow,
Structure fire, and numerous subjects looting

10-15 to get rid of this looter..

10-4

187 would be the police code for murder
so the song is saying a cops being murdered

187 is the police radio code for homicide