A suicidal Navy veteran who was allegedly suffering from post-traumatic stress disorder was shot dead by four police officers last night after warning a crisis hotline that an encounter with the law 'would not end well'. William Poole, 52, was killed by officers from the Gaston County Police department outside his home in Gastonia, North Carolina, Monday night. Police say they found him sitting on a lawnmower with a handgun, and that he opened fire after they approached him. Shot dead: Officers from Gaston County Police in North Carolina killed William Poole, 52, on Monday night. Police are pictured above on the scene . The officers then shot back, killing him. They had been sent to his home by concerned workers at the National Veterans Helpline. The crisis service had taken a call from him in which he said was going to kill himself - and not to send anybody to his house because it would 'not end well'. 'Excessive': Robert Hinson, Powell's son-in-law, spoke out after the shooting . None of the officers was harmed. Robert Hinson, Poole's son-in-law, told news channel WSOCTV he was on the phone with him moments before the death. Hinson, who lives on the same street as Poole, said he had only just hung up when he heard shots ring out. He said: 'Next thing I knew I'm hearing boom, boom, boom - sounded like the Fourth of July went off.' Hinson said that Poole had PTSD, but that 'he never tried to hurt anybody'. He told local news station WBTV that Poole had served with the Navy in Beirut. He characterized the police response as 'excessive'. Hinson said: 'I ran out the door and I see four county officers with their guns drawn and my father-in-law laying on the ground.' At a press conference Monday night, Gaston County police chief James Buie said: 'This is an unfortunate situation and our thoughts and prayers go out to all that's involved'. The four officers have been put on administrative leave. They have not been named. The shooting is being investigated by state authorities and Gaston County Police's professional standards unit. Suicide call: Police were sent to Poole's home after he phoned a veterans' crisis line and said he was suicidal. He also warned against sending anybody as it 'would not end well'
William Poole, 52, was killed in Gastonia, North Carolina, on Monday night . He opened fire on police while sitting on a lawnmower outside his house . Earlier that night he called veterans' crisis line and said he was suicidal .