An updated federal indictment accuses the man accused of hatching a plot to assassinate a Texas judge has tried to silence witnesses from his jail cell.

The amended indictment, which was returned last month by a federal grand jury in Austin, says Chimeme Onyeri passed notes to a fellow Travis County Jail inmate to call six witnesses and tell them to say nothing to investigators.

The indictment adds six counts of witness tampering against Onyeri. Also charged in the November 2015 shooting are Marcellus Burgin and Rasul Scott.

The three are accused of shooting state District Judge Julie Kocurek, who recovered from her wounds and has since returned to work.

All three have pleaded not guilty to all charges.