Mr. Jones was being tried on unrelated assault and robbery charges, Mr. Antenen said.
He showed a passport in the name of Naftali Triplett, who is wanted for an assault unrelated to the other crimes.
Mr. Robison is serving a prison term for an unrelated assault.
The man was arrested on charges stemming from an unrelated assault on Aug. 14, the date of the last shootings.
The police said today that the suspect had bought the murder weapon a day earlier, even though he was under indictment for an unrelated assault.
The police, in hopes of increasing the pressure against Mr. Guica, arrested him in July on unrelated assault and weapons charges.
The officer, Craig Yokemick, 35, was also indicted in the unrelated assault of a Westchester County schoolteacher, a case that caused him to leave the force.
On that basis Simpson was arrested on September 21 on a warrant for an unrelated assault in Greensboro.
After advising Simpson of his Miranda rights, the arresting officers briefly questioned him about the unrelated assault.
On the 13th, 400 Catalan militia occupied Cabrera in an assault apparently unrelated to Bayo's expedition.