A California man pleaded guilty to two counts of harassment after sending fake ransom messages to the family of missing Tucson woman Nancy Guthrie, authorities announced Thursday. Derrick Callella, 42, admitted he called and sent text messages to Guthrie’s family on Feb. 4 asking about a bitcoin transfer, according to the U.S. Attorney’s Office for the District of Arizona. Callella acknowledged he knew an earlier ransom demand had been made.