What would drive well-educated girls from a well-off suburb to become armed robbers? 48 Hours examines the case of four Texas teen-agers charged with armed robbery after allegedly pulling a string of stickups last year. Drugs and Money: Aroun... (more)d Houston, Kingwood has a reputation of being an oasis from urban problems. But growing up there did not keep four teen-age girls out of serious trouble. Bernard Goldberg reports on this unusual case. Teen-agers On Trial: After two of the girls pleaded guilty, they had to persuade a jury that they deserve mercy. But the prosecutor wanted them to serve prison time. Another girl pleaded innocent, determined to avoid prison altogether. Find out what the jury decided.