Newly released police reports say authorities investigating nine nighttime drive-by shootings in Phoenix believed to be the work of a serial killer have recovered bullet casings from some of the crime scenes.

They also were given vehicle descriptions in at least three of the attacks.

Witnesses described how the victims were attacked as they stood outdoors by a stranger who fired a handgun from a car and then fled the area.

Police say the documents were released in response to public records requests from news organizations.

In all, seven people have been killed and two others wounded in the shootings.

The attacks are occurring in two predominantly Latino neighborhoods located about 10 miles apart.

No motive has been established.

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