08/30/2010 02:50 pm ET Updated May 25, 2011

Drew Peterson's Son Suspended After Testifying That He Hid Father's Guns

The son of murder suspect Drew Peterson has been suspended from his job at the Oak Brook Police Department, following his testimony last week.

Stephen Peterson was placed on paid leave Thursday, pending an internal investigation, according to an Associated Press report.

Oak Brook Village Manager David Niemeyer refused to explain Peterson's suspension to the AP. But WLS-TV and the Chicago Tribune are both reporting that he was placed on leave because he admitted to hiding his father's illegal weapons in his home.

After Stacy Peterson, Drew's fourth wife, was reported missing in October of 2007, Drew approached his son with two or three guns, according to the Tribune. On Monday, Stephen testified that the weapons "were his favorites and he didn't want anything to happen to them."

One of the weapons in the cache was an AR-15 assault rifle, WLS reports. That weapon is illegal in Illinois.

Drew Peterson is facing trial this year for the 2004 murder of his third wife, Kathleen Savio. The case was ruled an accident until Stacy's disappearance, when it was re-opened and deemed a homicide. Stacy has still not been found, so no charges have been filed in that case, though Drew is the only suspect in her disappearance.

The former Bolingbrook police officer is also charged with possessing an illegal weapon. Stephen has not been charged, though he admitted to keeping the AR-15 in his home.

Stephen's suspension is not the first blemish in his six-year career at the Oak Brook P.D. In fact, he's been suspended at least five times, according to his record.

Most notably, he was chastised for driving an Oak Brook squad car to a grand jury investigating Stacy Peterson's disappearance, where he testified in full police uniform. He has also been suspended for running improper background checks on village employees and making rude comments to citizens, according to the Tribune.

His father's trial was set to start this summer, but has been delayed pending the resolution of motions surrounding the admission of hearsay evidence. The trial won't start until next year at the earliest.