LOS ANGELES — The judge in the Anna Nicole Smith drug conspiracy trial said Tuesday he doubted prosecutors can prove key charges against two doctors and the lawyer-boyfriend of the late Playboy model.

The two counts targeted by Superior Court Judge Robert Perry are at the heart of the case, accusing the three defendants of conspiring to prescribe, administer and dispense controlled substances to an addict and obtaining and dispensing prescriptions by fraud and use of false names.

Perry raised the issue after a juror sent him a note asking for a copy of the charging document. He said he was unsure about sending the jury the entire document, indicating it might change.

"I'm not sure you can make your conspiracy counts one and two from what I've heard," Perry told prosecutors. "But I am not ruling on that now."

Dr. Sandeep Kapoor, Dr. Khristine Eroshevich and Howard K. Stern have pleaded not guilty. They are not charged with Smith's overdose death in 2007.

Perry also questioned the propriety of some of the overt acts cited in connection with the alleged conspiracy.

An overt act is an alleged action by one or more defendants that prosecutors contend proves the conspiracy and other crimes. There are 45 overt acts in count one of the felony complaint and 19 acts in count two.

"There are a number of overt acts I think are improper," the judge said, "at least eight or 10."

Prosecutors are nearing the end of their case in the fourth week of the trial. Once they rest, the judge has the authority to dismiss any charges he thinks are not supported by evidence.