Green’s Dictionary of Slang

1. (Aus und.) to assess possible sites for robbery oor brea-ins.

1895

C. Crowe Aus. Sl. Dict. 61: Prospecting, looking for something to steal.

2. (N.Z. prison, also P it) to work as the most subsurvient member of a gang prior to beiing a full member.

1991		B. Payne Staunch 93: [H]e went into corrective training a second time and I have my suspicions that the prospecting started there, the recruiting started there.
2001		D. Looser Boobslang [U. Canterbury D.Phil. thesis] 133/1: P it v. to work as a gang prospect [...] 147/1: prospect v. to carry out crimes or general chores for full members of a gang, in order to also become a full member of that gang.