The state agency overseeing local district attorneys is investigating another ethics complaint against Kenosha County DA Robert Zapf. 

Russ Beckman, the retired detective, says the issue stems from the concealing of cell phone tracking records from defense attorneys in two Kenosha homicide cases from 2010. 

Mr. Zapf prosecuted Julian Miller and Daniel Gonzalez in two separate cases. 

"There was denials of the cell phone tracking. There was perjury on the stand, testimony offered under oath that no cell phone tracking was used and it was clearly wrong," said Beckman. "It turns out cell phone tracking was used."

Mr. Zapf declined an on-camera interview but issued a statement saying he strongly denies the allegations. 

He called Beckman a "discredited and disgruntled former KPD detective who has an apparent agenda." 

CBS 58 contacted the director of the state Supreme Court's Office of Lawyer Regulation. They will not comment until the investigation is over.