The chief said it would be several months before the investigation was completed and presented to the civilian Police Commission to determine if it was within department policy. Meanwhile, the officers remain on non-field duties.
The commission will receive separate recommendations from Beck and the department's independent inspector general. The county district attorney's office will separately determine if the shooting was justified or if charges should be filed.
Beck said the department has found no witnesses who saw the confrontation between Ford and the officers. He appealed for any possible witnesses to come forward.
Steve Lerman, an attorney for Ford's parents, didn't immediately respond to a request for comment. A voicemail left for Ford's parents wasn't immediately returned.
Ford's parents have filed a federal civil rights lawsuit and $75 million claim against the city alleging the two gang officers knew Ford from the neighborhood and were aware he had mental problems.
Beck said he had no indications thus far that the officers involved knew anything about Ford's mental condition.
Lerman has said his investigator found witnesses to support his case but refused to divulge details. Beck said police tried to reach witnesses listed by the family's legal staff but were unable to successfully speak to any.
The suit also claimed that the city, LAPD and 10 unnamed superiors or other officers were part of a culture that tolerated civil rights violations, including racial profiling and excessive force against blacks.
Tyler Izen, president of the Los Angeles Police Protective League, said in a statement that the autopsy presented only "one set of facts among many hundreds being collected and assessed in the ongoing investigation."