Check this tweet out from the Lynx PR account:
McCarville last played for the New York Liberty and was on the suspended list since 2011, so it's clear that the Liberty signed and then traded her in this deal
Stay tuned as we learn more on the details of this move.
UPDATE on February 8, 2013 3:10 PM ET
In the deal Candice Wiggins was traded to the Tulsa Shock, helping fill a need at guard due to Temeka Johnson and Ivory Latta leaving in free agency.
UPDATE on February 8, 2013 3:13 PM ET
Deanna Nolan was signed by the Shock and then traded to New York in the deal. Nate has his insights on this move in an all out article which you can read here.