Grigg Park is next to Grigg Place, which was named after Cr Albert Grigg (but is not a 'place' - in the sense of a piazza or square) and so therefore also bears his name. Lynch St is on the other side: he was a councillor also. Snook (of Snook Crescent) was shot in the Town Hall.
It's possible that the park was thought of as a 'place' in the sense of square (piazza, Platz), and that it was named for the councillor first, and the street name followed from that.
Pathika Jones has written a long article about the park for the Fremantle Shipping News website.
Fremantle Shipping News website article by Pathika Jones.
Garry Gillard | New: 27 February, 2018 | Now: 22 August, 2018