(CBS) -- Several sources familiar with the federal investigation into the Laquan McDonald shooting tell CBS 2 Chief Correspondent Jay Levine a prime focus of the probe is why accounts of the other officers bears little resemblance to the dash cam video of the shooting.
"There is an investigation right now by the U.S. Attorney on the event and all parties involved as it relates to Laquan McDonald," Mayor Rahm Emanuel said at a press conference Monday.
Police reports detail interviews with all 10 officers who were there when McDonald was shot and killed including Jason Van Dyke, who is now charged with first degree murder.
The report quotes Van Dyke saying: "(Laquan), raised knife across chest over shoulder, pointed knife at (me)…(I) believed (Laquan) was trying to kill (me)."
Van Dyke's partner and driver, Officer Joe Walsh, raced around the car, pointed his weapon but didn't shoot. He told an investigator he: "believed (Laquan) was attacking Van Dyke with knife attempting to kill (him)."
In the video released two weeks ago, Van Dyke and Walsh are seen driving up, as McDonald walks down the centerline of Pulaski Road, the officers getting out of their SUV and Van Dyke almost immediately opening fire on McDonald as he angled away from them.
Officer Dora Fontaine said:"(Laquan) raised (his) right arm toward (Van Dyke) as if attacking (him)."
"It didn't happen and the other officers, and this is the other part of the code of silence, the other officers who didn't back up his story then, tell a different lie which is, we saw nothing," said University of Chicago law professor Craig Futterman.
Among others following McDonald was Officer Joe McElligott, who said: "…in pursuit...out into the middle of Pulaski...heard multiple gunshots did not see who fired…"
Officer Daphne Sebastian: "…heard multiple gunshots and (Laquan) fell to the ground continued moving…(I) did not know who fired shots."
Officer Arturo Becerro said: "(I) saw (Laquan) in the middle of the street flailing arm, saw a knife in (his) hand, heard multiple shots, did not see who fired."
"Every one of those officers were doing the right thing beforehand then lie and lie in official police reports," Futterman said. "Everyone was there and this video indisputably shows, that's just simply a lie."
"If people are not telling truth but believe there's a permissible culture that enables that rather than holds them accountable, we have a problem because people won't trust it," Emanuel said Monday.
Until now, action against any officers in a case is delayed until all criminal charges are dealt with. In this case, that means the case against Van Dyke. But with the mayor on the hot seat and the department reeling, some feel that policy is about to change, giving IPRA the go ahead for disciplinary action against any officers who knowingly made false statements sooner rather than later.
WBBM's Steve Miller reports that new IPRA head Sharon Fairley is asking Chicago Inspector General Joe Ferguson to investigate the officers' statements.
for more features.