Slain Woman's Sister Calls Drew Peterson "An Idiot"

The sister of Kathleen Savio says Drew Peterson --a former police sergeant from suburban Chicago -- is "an idiot" for  allegedly cracking  jokes during his arrest Thursday for allegedly killing Kathleen, his third wife . 

Peterson reportedly said while being cuffed :  "I guess I should have returned those library books."

Peterson, 55, is accused on orchestrating the 2004 death of Savio, who was found drowned in her bathtub.  At the time, her death was ruled an accident. The case was re-opened only after his fourth wife, Stacy,  turned up missing more than three years later. Stacy has never been found.

Peterson is expected to plead not guilty when he is  arraigned Friday on first-degree murder charges.  He's currently being held on a staggering $20 million bond.

Savio's sister, Susan Doman, appeared on ABC's Good Morning America Friday and said that the arrest was a long time in the making and comes as a relief to the family.

Peterson was arrested before a scheduled interview for a security job with a Nevada brothel featured on HBO's Cathouse.

Doman said the timeliness of the arrest came as "a big relief, because he wasn't going on all these shows, going around laughing and joking."