Cook County prosecutor fired amid allegations he lied under oath

CHICAGO (WLS) -- A Cook County prosecutor has been fired amid allegations he lied under oath in the 2012 shooting investigation of Chicago police officer Del Pearson.

Now, Cook County State's Attorney Anita Alvarez said the prosecutor's actions could lead to criminal charges.

Alvarez calls this a "very serious issue", and a "difficult time" after a 13-year assistant in her office - with an otherwise solid reputation - was exposed for lying under oath. The result may carry significant consequence for an important case.

Tactical officer Del Pearson nearly lost his life three-and-a-half years ago when he was shot during a foot pursuit. He lived and returned to the force. The alleged shooter, Paris Sadler, was charged and is awaiting trial. A gun found in his mother's home was linked through ballistics to the shooting.

Assistant State's Attorney Joe Lattanzio is accused of lying on the stand about a statement he took from Sadler's mother a day after the shooting.

The fib under oath has to do with whether Sadler's mother had given police clear permission to enter the home. Sadler's mother recorded the visit on an iPad. That recorded version revealed the lie, and the state's attorney has now fired the Lattanzio.

"As a prosecutor who has done this job now for 29 years, I am appalled, I am livid, I am outraged by the actions of this particular assistant," Alvarez said.

The state's attorney says she's referring the case against Lattanzio to the Attorney General's office for possible criminal prosecution.

The more immediate question is: if the there are questions about the legal validity of the home search, does it jeopardize the case of an attempted murder of a police officer?

"Our motion says that there was a search of our client's home and that there was not lawful consent to conduct that search," said Amy Campanelli, a Cook County public defender.

"We may or may not, depending on the ruling. There is a possibility that we would lose some pieces of evidence, but again, that we won't know until he makes his final ruling. But no, the case is still viable, the case is still going on," Alvarez said.

Judge Thaddeus Wilson will ultimately rule on what evidence stays in, and what's excluded.

If he finds the police visit and search to have been unlawful, it raises at least the possibility that the gun evidence would be out.

In addition to referring the case against Lattanzio to the Attorney General, the state's attorney's office is reviewing previous cases he was involved in.