Suspected of being the "Boxcar Murderer", Bob was part of the Freight Train Riders of America, a boxcar gang that preys upon fellow rail-riding hobos. Arrested in March, 1995, in a rail yard near Sacramento, California, Silveria was charged with the murder of transient William Pettit, found dead in a boxcar in Northern California.
Silveria has also been linked to 13 other boxcar murders in Oregon, Utah, California, Arizona, Kansas and Washington state spanning from 1981 to 1995. The victims, mostly drifters, were stabbed or bludgeoned to death and robbed of their meager possessions. While in custody Bobbie claimed all his kills were gang related hits. Having betrayed his secret boxcar brotherhood by talking of the murders, Silveria believes he will soon be executed by fellow rail-riding gangster.