Graffiti vandals could reportedly face up to 14 years in jail after a pair of ill-shaped swastikas and white supremacy slogans appeared in the carpark of Midland Gate Shopping Centre.

A local resident who found and photographed the graffiti on Monday said he was concerned as it did not appear to be a case of children misbehaving.

The ill-shapen swastika that appeared in Midland in December.

"They don't know their swastikas, that's for sure," the resident said of the roughly spray-painted shapes.

"But I don't think it's just kids up to no good. The slogans that were painted with them saying 'white lives matter' seem a bit more adult than that.