Metal Stars

I've seen in a movie once. Apparently, there is sharp metal stars that are designed to extinguish the tires (if a vehicle rolls over them). What are their names?

Caltrops.

Not 100% sure on the spelling.

[Edit]
Yep, it's (one of) the correct spelling (s).

pointed metal stars.

Being a ninja star or spike tires

Caltrops! They originated back when people rode horses, and sharp metal spikes would cripple horses prosecutors if people fleeing the spread behind.

NINJA stars!

Shuriken!

where Im their points known. If your talking use law enforcement, their tips road called

Tell you access using the cops SPIKE STRIPS?

Caltrops?
do you think of the ear thingies ninja thrown on the ground?
either the road or spikes used by police.

Tire spikes?

things explody tires