Never ask a question unless you already know the right answer

In the category of lawyers should never ask a witness a question they don't already know the answer to, I stole this gem from Brownell's Just Jawin'

In a trial, a Southern small town, the prosecuting attorney called his first witness, a grand-motherly, elderly woman to the stand.

He approached her and asked, "Mrs. Jones, do you know me?" She responded, "Why, yes I do know you, Mr. Williams. I've known you since you were a young boy, and frankly, you've been a big disappointment to me. You lie, you cheat on your wife, you manipulate people and talk about them behind their backs You think you're a big shot when you haven't the brains to realize you never will amount to anything more than a two-bit paper-pusher. Yes, I know you."

The lawyer was stunned! Not knowing what else to do, he pointed across the room and asked, "Mrs. Jones, do you know the defense attorney?" She again replied, "Why yes, I do. I've known Mr. Bradley since he was a youngster, too. He's lazy, bigoted, and he has a drinking problem. He can't build a normal relationship with anyone and his law practice is one of the worst in the entire state. Not to mention he cheated on his wife with three different women. One of them was your wife. Yes, ! I know him."

The defense attorney almost died.

The judge asked both counselors to approach the bench, and in a very quiet voice, said, "Neither of you guys had better ask her if she knows me."

Now let me tell you one of my daddy's favorite stories. His father was a fox-hunting buddy of the prosecuting attorney for Richmond County, the late Elsie Webb. My grandfather was testifying as a character witness for a defendant who was being prosecuted by Webb in court.

After testifying what a fine man the defendant was, Webb cross-examined my grandfather.

"Mr. Myers, are you a drinking man?" Webb asked.

"Yes, I take a drink now and then," my grandfather answered.

"When was the last time you had a drink, Mr. Myers?" Webb asked.

"I'd rather not say," my grandfather replied.

"Well you're sworn in as a witness and you gotta say. So when was it?" Webb shot back.

"Well, if you insist," my grandfather replied. "It was last night while we was fox-hunting and you handed me the pint bottle from your back pocket."

"Come down, Mr. Myers, no more questions," Webb concluded hastily.