CHICAGO, IL - The spotlight during a fifth day of testimony at ex-cop Drew Peterson's murder trial is expected to fall on the shoddy investigation that followed the discovery of his third wife's body.
 
Among those prosecutors are slated to call to the stand Tuesday is a retired state police sergeant Patrick Collins and crime-scene investigator Robert Deel.
 
Investigators have conceded earlier they weren't as thorough as they could have been after finding Kathleen Savio dead in her bathtub in 2004. They quickly concluded her death was accidental and no physical evidence was collected.
 
The 58-year-old Peterson was only charged in Savio's death after his fourth wife, Stacy Peterson, went missing in 2007. Savio's body was then exhumed and her death reclassified as a homicide.