Casey Anthony's defense team on Friday deposed several law enforcement officials.

Lead attorney Jose Baez said 13 law enforcement officers who were on the "outer edges of the investigation" were deposed Friday morning. The officers refused to answer questions as they were leaving the state attorney's office.

According to Baez, the state attorney has a rule that any law enforcement officer involved with a case in any manner is listed as a "category A" witness, meaning he or she has material evidence that is likely to be used in trial, so the defense has to depose them. Baez said many of the officers deposed Friday were "category C" witnesses, which do not require deposition.

"We really don't know what they have to testify to, so we're just going to eliminate the important ones, take them and (depose) them for another day," Baez said Friday morning. "And those who really had no participation in our case, we're going to eliminate today."

Over Thursday and Friday, Anthony's defense team will depose about 35 law enforcement officers.

The state attorney's office said it stopped using classifications years ago and anyone who touches a case in any way is considered a witness.

Anthony is charged with first-degree murder in the death of her daughter, Caylee Anthony.

Caylee was 2 years old when she was reported missing in July 2008. Her remains were found in a wooded area in east Orange County in December 2008.

Anthony has pleaded not guilty. Her trial is scheduled to begin in May.