Based on physical evidence _ including a rifle found in April month buried near the doctor's house and a match between fibers found near the murder and others found in Kopp's car _ officials said they had decided to issue a warrant for his arrest in the killing of Dr. Barnett Slepian. Kopp, a fugitive, has until now been described only as a material witness and a nationwide warrant had been issued so that he could be held for (questioning).  
 Verb: questioning
No