The newspaper says the police department and its attorney at the time, current Los Angeles City Attorney Carmen Trutanich, claimed the lead bullet fragments were planted by neighborhood residents who oppose the presence of the firing range.
State investigators launched their investigation in April 2008 after receiving complaints from neighbors.
According to the L.A. Times, investigators found elevated levels of lead in the sandbox at Towers Elementary School, prompting school authorities to replace the sand.
There are no reports of anyone being injured by a bullet fragment from the range.
Redondo Beach officials say they are still working with state and local authorities to resolve issues associated with the firing range.