Ecuadorian labourer Diego Pillco was jailed for 25 years in 2008 after he was convicted of strangling the Waitress director in November 2006 when she caught him trying to burgle her apartment.
He had been renovating another apartment in the New York building at the time and Shelly's husband, Andrew Ostroy, subsequently filed a wrongful death suit against the construction company which employed Pillco.
Ostroy alleges his wife would still be alive if bosses at Bradford General Contractors (BGC) hadn't hired an illegal immigrant.
Now Ostroy's legal battle has taken a step forward after the judge overseeing the case at New York's Manhattan Supreme Court granted his request to use the minutes from Pillco's grand jury hearings, which are usually kept secret.
Officials at the district attorney's office had opposed the move, insisting the proceedings should "remain secret to protect the identity of witnesses", according to the New York Post.
But State Supreme Court Justice Louis York dismissed the challenge and ordered the documents to be handed over.