Keon King, the Philadelphia man charged with abducting Kada Scott, might've been working with an accomplice. 

Police say King and someone they believe to be an accomplice were seen in the area of Ada H. H. Lewis Middle School in East Germantown, where Scott's body was found in a shallow grave, on cameras at the Awbury Rec Center, which is next door.

Police were called to the vacant middle school two different times during the two-week search for Scott. 

Sources said the first tip that directed police to Ada H. H. Lewis Middle School was on a 911 call. During that search, police say they found Scott's cell phone case, a bank card and glasses. 

Then, two days later, sources said police received another tip via email with a more urgent directive to go back to Ada H. H. Lewis Middle School and keep looking. The details were a bit more specific, according to prosecutors. 

Prosecutors said the identity of the tipster is not known, but their involvement is under investigation.

Police say Scott, 23, was kidnapped by King outside the Chestnut Hill living facility where she worked on Oct. 4. She was likely killed 20 minutes after she got into a 2008 Hyundai Accent that was driven by King, according to investigators. 

Investigators believe King then brought Scott's body to the area behind Ada H. H. Lewis Middle School, where her body was found buried in a shallow grave on Saturday. Amid the investigation, Philadelphia City Councilmember Cindy Bass has called for the school to be demolished.

The cause of Scott's death is still under investigation. The Philadelphia Medical Examiner's Office, according to sources, is using a forensic anthropologist as pathologists examine Scott's remains.

King is still being held on $250,000 cash bail as prosecutors continue to build a homicide case against him. He was arraigned Tuesday on conspiracy and arson charges connected to allegedly burning a car that police believe was used to move Scott to multiple locations including the school where her remains were found.

CBS News Philadelphia reached out to King's lawyer, Shaka Johnson, to comment on the case, and we've yet to hear back.