D.C. Mayor Marion Barry has been charged with 14 crimes that fall into three categories: 1 count of conspiracy to possess cocaine powder and crack cocaine, a misdemeanor; 10 misdemeanor counts of possession of cocaine or crack cocaine; 3 felony counts of perjury.

The 12 members of the jury must decide each of the 14 counts separately and return a unanimous verdict of guilty or not guilty on each charge. To find guilt, the jurors must find that the government proved each charge "beyond a reasonable doubt."

Although the indictment charges that the crimes were committed "on or about" certain dates or periods, the judge instructed the jury yesterday that it does not have to find "with certainty the exact date of the alleged offense." The jurors must find only that the government has proved "beyond a reasonable doubt that an offense was committed reasonably near the date or period alleged."

Judge Thomas Penfield Jackson told the jurors that reasonable doubt exists when a juror feels, "after careful and candid and impartial consideration of all the evidence" that the juror is "so undecided that he cannot say that he has a firm belief of the defendant's guilt."

"It is such a doubt as would cause a reasonable person to hesitate or pause in the most important transactions of life," the judge said yesterday. "It is, however, not a fanciful doubt, nor a whimsical doubt, nor a doubt based on conjecture. It is a doubt which is based on reason. The government is not required to establish guilt beyond all doubt, or to a mathematical or scientific certainty."

The judge also instructed the jury that it is not to consider in their deliberations whether the prosecution and investigation of Barry was improper. He told them he already has ruled that it was "properly commenced and not brought for improper purposes." He also told the jury that he has found that the undercover operation in January at the Vista Hotel, which resulted in the mayor's arrest, was legal and "conducted in accordance with the law."

"Conduct such as purchasing drugs and providing drugs to targets of investigation is lawful when carried out by government agents or supervised cooperators during an undercover operation in an attempt to apprehend persons who had been engaged in illegal activities," the judge said. "If you hold any opinions or feelings to the contrary, I instruct you that you must set them aside entirely and you may not consider or discuss them."

The judge told the jury, however, that they may consider whether Barry was a victim of entrapment. If they find that he was, they must acquit. The judge stressed that if jury finds that Barry was predisposed to smoking crack cocaine "the fact that law enforcement officials or their agent merely afford opportunities for him to do so does not constitute entrapment." Predisposition may be shown by presenting evidence of prior similar criminal conduct.

To find the mayor guilty of conspiracy to possess cocaine, the judge instructed the jury that they must find that the government proved that from the fall of 1984 to Jan. 18, 1990, Barry had an agreement with at least one other person to possess powder or crack cocaine. They must also find that Barry knowingly participated in the conspiracy.

The judge defined conspiracy as a "criminal partnership" between at least two people to do something unlawful. The judge told the jurors that the alleged members of the conspiracy do not have to know each other or all agreed with each other to participate.

To find the mayor guilty of the 10 separate misdemeanor counts of possession of cocaine or crack cocaine, the judge said the jury must find that Barry either had direct or physical control of cocaine or crack "on or about" the time charged and that he "did so knowingly and intentionally."

To find Barry guilty of the three felony counts that he lied to a federal jury on Nov 10, 1989, the judge said the jury must find that Barry testified under oath before a grand jury and that he knowingly gave false answers to questions about his knowledge of Charles Lewis's drug use and whether he gave or received cocaine from Lewis. The judge said that if the jurors find that a question asked in the grand jury was ambiguous and that it was subject to more than one interpretation and {Barry} truthfully answered one reasonable interpretation of the question, then his answer would not be false.