Lasalle was one of the InGen Hunters. In Jurassic Park: Trespasser he is described by John Hammond:

"Lasalle was a disciple of Roland's, sometime poacher, fancied himself a master hunter. An ex-policeman from South-Africa, sort of a soldier or fortuna character. Known as "The Maharaja" to his fellows, highly skilled but only works alone. He was meant to radio for picking up from the communication station"
John Hammond(src)

When Hammond is listing the "Missing" hunters, he says:

"Marden, A.S., Still missing. Karamcheti, V., Still missing. Sullivan, R.M., Still missing. LaSalle, P., Still missing. Van Horn, S.T., also still missing. Lystrata, A.L., Deceased"
John Hammond(src)

It is not known if LaSalle survived the hunt, but it can be assumed that he died when the hunters were ambushed in the tall grass. This is heavily supported by a concept art (seen to the right)


A Trespasser storyboard image of an InGen Hunter is assumed to be Lasalle.