For two former high-ranking officials implicated in the Jerry Sandusky sex abuse scandal, today’s preliminary hearing in Harrisburg will likely mark the beginning of a probe into just how much a key state witness knew and just how much that witness did in response.

Although the state Attorney General’s Office would not confirm what state witnesses would appear, The Harrisburg Patriot-News reported Thursday that Mike McQueary — the graduate assistant who allegedly saw Sandusky rape a young boy in 2002 — would be taking the stand today. The prosecution is looking to hold for trial charges against former Penn State Athletic Director Timothy Curley and former Vice President of Finance and Business Gary Schultz.