EL MONTE (CBSLA) — Three minors and an adult had three cash boxes in the trunk of a car they crashed at the end of a car chase Wednesday, and police are trying to figure out where all the money came from.

Officers first tried to stop the driver for having paper plates just before 3 a.m. in the Claremont area. The driver took off, leading a brief chase onto the 10 Freeway and into Baldwin Park, where they crashed at Stewart and Peck Road.

Two of the suspects took off running after the crash, but were caught quickly, while the two others stayed on the scene. All four are in custody.

(credit: CBS)

But questions remain about three cash boxes found in the trunk of the car. No burglaries have been reported in surrounding areas, and investigators are now trying to determine where the cash boxes came from.