Crime is paying for 48 Hours Mystery.After fighting each year for a spot on the prime-time schedule, the long-running newsmagazine is looking more secure since it's been turned into what could be called CSI: CBS News. The show still has its single-topic format, but gone are the long-winded intros by a CBS anchor, so viewers now get right into the story. The changes have resulted in decent ratings and a different kind of show for CBS News. While 60 Minutes wouldn't touch the Laci Peterson murder case — which has offered up endless fodder for lurid supermarket tabloid covers — 48 Hours Mystery dove right in. But the show is at its best when it takes a Law & Order-esque look at less high-profile whodunits drawn from real life, such as the murder of a Williamsport, Penn., woman by her surgeon husband. This week's episode (Saturday at 10 pm/ET on CBS) features the grisly tale of an unassuming fourth-grade teacher who hacked her husband to death, then ran errands with his body in her car. Says executive producer Susan Zirinsky, "I wanted to call that show 'A Very Desperate Housewife.'"