Acquaintances of a man arrested for the shooting death of another suspected methamphetamine user told detectives he was dangerously unstable and often accused people at gunpoint of things they did not do. A witness in the investigation of Warren Scott Flinn’s homicide said suspect Shane Caleb Smith, 38, is known as “Psycho Shane” and sometimes speaks of imaginary people and vivid hallucinations, according to court documents filed Wednesday. Another witness said Smith had a “large pistol” and was pointing it at people at a home in Spokane Valley May 12 - the night detectives believe he shot Flinn. Detectives say Smith said he shot Flinn twice in the back of his head during a dispute over cigarettes, but acquaintance Forrest Fennell said he believes Smith killed Flinn over methamphetamine and said Smith was dangerous and known to be “crazy,” according to a search warrant filed today. That search warrant authorized detectives to search Smith’s home at 6704 E. 3rd Ave., in Spokane Valley Tuesday. Smith was arrested there and is in jail on a charge of second-degree murder. Detectives seized two handguns from the home, including a .22 caliber pistol believed to be the murder weapon, as well as ammunition. They also found some of Flinn’s belongings. Smith has felony convictions that prohibit him from lawfully possessing firearms. He remains in jail on $150,000 bond after appearing in Superior Court Wednesday via video from the jail. Flinn was found badly injured near railroad tracks in the 300 block of North Lake Road in Spokane Valley when deputies responded to a possible trespassing call there May 13. He died May 16 at a local hospital of what the medical examiner’s office ruled were gunshots to his head. Smith told detectives he and Flinn had been out “scrapping” for metal near the railroad tracks on Lake Road when they began to argue over cigarettes, according to detectives. Investigators believe Flinn is a transient, but court records show he lived at an address on South Audubon Street in September. He also spent time in Florida and California, where he has felony convictions for burglary. Smith’s criminal history includes convictions for drunken driving, second-degree malicious mischief, obstructing a law enforcement officer, residential burglary and second-degree escape, according to news archives.