BOLINGBROOK , Illinois ( CNN ) -- The disappearance of a suburban Chicago police sergeant 's wife is now being treated as a potential homicide , and her husband is a suspect , authorities said Friday . Stacy Peterson , 23 , has been missing from her suburban Chicago home since October 28 . In another development , a judge signed an order to exhume the body of Drew Peterson 's third wife , who was found drowned in a bathtub in 2004 , said Will County State Attorney James Glasgow . Peterson , 53 , said he last spoke to 23-year-old Stacy Peterson -- his fourth wife -- the night of October 28 . Drew Peterson initially told the media he believed his wife ran off with another man , but he has n't repeated that accusation . CNN has been unable to contact Drew Peterson for comment . The couple have been married four years and have two children , who have been interviewed for the investigation , Glasgow said . Drew Peterson also has older children from a previous marriage . Investigators have twice searched the couple 's home and vehicles , and removed several items , including computers , said Illinois State Police Capt . Carl Dobrich . Drew Peterson allowed a limited search on the night his wife was reported missing , but investigators were not allowed to look throughout the entire house and were given access to only one of the vehicles at that time , Dobrich said . `` Early on , we looked at this as a missing persons case , but also believed strongly ... it was strongly starting to look at Drew Peterson as being a person of interest , '' Dobrich said . `` I would say that right now , Drew Peterson has gone from being a person of interest to being a suspect . '' New information turned up during the investigation also raised questions about the death of Peterson 's third wife , Kathleen Savio , which was ruled an accident by a coroner 's jury , Glasgow said . `` There are strong indications that it was a homicide , '' he said . `` That 's why we are doing the exhumation , because there are tests that need to be done that were n't done during the first autopsy . '' Watch why authorities want to exhume the body » . Glasgow cited abrasions on Savio 's body and a gash on her head that could not be readily explained . `` Our main thrust is to determine whether or not it was a homicide , and as we do that , we will see if there is any evidence that implicates anyone , '' he said . Glasgow , who was not state attorney at the time of Savio 's death , said he reviewed the case file before deciding to reopen the case . `` With 29 years of experience , there was no doubt in my mind it was n't an accident , '' he said . `` That was clear . '' In 2002 , Savio was charged once with battery and once with domestic battery against her husband , but was found not guilty at trial , Glasgow said . Another time , she tried to bring domestic battery charges against Peterson , but no charges were ever filed . Savio 's sister , Sue Doman , said Savio expressed fear of Drew Peterson . `` She told me all the time , 'He 's gon na kill me . It 's gon na look like an accident , ' `` Doman said . Doman said she did n't believe her sister could have died in the way the investigation concluded . `` I do n't understand accidental drowning . You just do n't drown in the bathtub , especially a small whirlpool . You just do n't do that , '' she said . Meanwhile , friends and family of Stacy Peterson said she expressed concerns about her husband . A friend , Steve Cesare , has told CNN he received e-mail from her describing her relationship as abusive . The woman 's aunt , Candace Aikin , of El Monte , California , said Stacy Peterson confided in her that there were problems during a visit to the Peterson home in suburban Chicago last month . `` She said that she was afraid because he was following her around 24/7 , even inside the house , '' Aikin said . `` He was very obsessed and stalking her , even inside her house . She was very , very full of stress and just not happy in her marriage at all , '' Aikin said . E-mail to a friend .
NEW : Judge signs order to exhume the body of Peterson fourth wife . Stacy Peterson has said he believed his third wife left him for another man . Police : Case shifts from a missing persons search to a potential homicide . Friends and family : Drew Peterson 's expressed concerns about her husband .