A 10-year analysis of prosecutions under a law meant to punish artifact looters shows most people convicted never go to prison.

Archaeologist and former academic Robert Palmer has found in his review of cases from 1996 to 2005 that of the 83 people found guilty, 20 went to prison and 13 of those received sentences of a year or less. Another study found only 14 percent of artifact looting cases are ever solved.

Jeanne and Jericca Redd were given probation after pleading guilty to several felonies related to a sweeping federal investigation into grave robbing and artifact trapping in the Southwest.