After we got an appearance by a Breaking Bad guest star in the last episode we get an appearance by one of the show's stars in Anna Gunn. She played a slutty woman whose previous husband died under mysterious circumstances and now she was accused of murdering her last husband. The role was not well-suited for her, similar to the Vivica A. Fox appearance in a similar role last season.
As for the episode as a whole, forgettable is probably the best way to describe it. Just writing this review now, a day after I watched it, I'm not even sure what the verdict was (just kidding, it was guilty, like 95% of L and O's end.)