Authorities investigating the first serial killer in Phoenix in a decade say they have linked a non-fatal shooting to the case.

The revelation brings the number of shootings tied to the case to nine, including earlier attacks that resulted in seven deaths.

Police say Wednesday that the latest attack occurred in a central Phoenix neighborhood on July 11 when someone fired on a vehicle occupied by a 21-year-old man and a 4-year-old boy.

Neither was injured.

No other details on the shooting were immediately available.

In all, seven people have been fatally shot and two others wounded in attacks that began March 17.

Most of the attacks occurred in the blue-collar Maryvale neighborhood, though two shootings — including the latest — occurred in another part of the city.