KTVU has learned Deborah Madden was unlikely to be charged in San Francisco and a police source said the department was now trying to "move on" and learn from the scandal.

A source close to the investigation was "very confident" that the state attorney general will not file charges against Madden, the retired San Francisco Police crime lab technician accused of stealing cocaine and other drugs while on the job.

That source said it was unlikely the AG's office was willing to invest months of time and money to prosecute madden.

KTVU has also learned the police investigation centered on a special type of paper found in madden's house.

The paper is specifically used to wrap narcotics for testing in the police crime lab.

A source said San Francisco investigators "put all their eggs in one basket” by choosing to focus on the paper as proof madden stole from the job.

"I have not seen any evidence that affirmatively means that those papers were taken from that particular lab," said Madden's attorney Paul Demeester in a phone interview Thursday.

The news comes just two days after KTVU first reported a shake up in the SFPD command staff.

Assistant Chief Kevin Cashman and Investigative Commander John Loftus this week were demoted to the rank of captain.

Those two command staff members and Assistant Chief Morris Tabak -- who is expected to retire later this year -- all had roles in either supervising or investigating the troubled crime lab.

A source says disciplinary charges are expected against others at the crime lab.

Assistant chief jeff godown declined to talk about personnel issues, but said the department is focused on rebuilding the lab.

"After overseeing the lab investigation, there were definitely warning signs a long time ago that I think would've made a difference as far as had the warning signs been looked at," said Godown.

The Attorney General's office Thursday declined to comment, but Chief George Gascon was scheduled to hold a press conference Friday to address the status of the crime lab.

Madden still faces charges in San Mateo County for possession of a small amount of cocaine.