Auburn police said a 47-year-old man shot and killed himself Wednesday afternoon on the Londonderry Turnpike after a brief motor vehicle pursuit. Officers had responded to a call just before noon about a possibly suicidal man with a handgun in Front Park on Bypass 28. When police arrived, the man jumped into his vehicle and headed south on the Bypass toward Derry, eventually pulling over to talk to law enforcement officials for several minutes. It was then he turned his gun on himself. The incident backed up traffic in the area for some time. Auburn police were assisted by the Derry police as well as Rockingham County Sheriff’s Office, Manchester Watershed Police and the New Hampshire State Police.