A Milpitas man accused of bludgeoning a dog to death with a hammer is facing additional charges alleging that he tried to silence a witness.
Alex Castro is in custody and awaiting trial since being arrested last year on suspicion of killing the 10-year-old cocker spaniel of his now ex-girlfriend.
Castro,47, is now accused of soliciting a Milpitas motorcycle club -- the Regulators -- to try to prevent a key witness from testifying.
Prosecutors say Castro mailed a letter to the leader of the club in October of 2007 asking the club to silence the witness.
Castro had previously been charged with felony animal cruelty, a charge prosecutors say makes him eligible to be sentenced -- if convicted -- under the state's "three strikes" law because of his previous felony convictions.