Authorities in Florida say that three people are dead and two are injured after a gunman opened fire at two locations in Union County on Saturday, according to WCBJ-TV in Gainesville, Fla.

At one site, Hubert Allen Jr., 72, walked into a Pritchett Trucking Co. facility in Lake Butler where he was once employed and shot David Griffis, the television station cited Union County Sheriff Jerry Whitehead as saying. Allen has been identitifed as the step-grandfather of Buffalo Bills running back C.J. Spiller. Griffis is listed in critical condition.

At the other site, Allen shot and killed Marvin Pritchett, the trucking-company owner, and Rolando Gonzalez-Delgado, one of his employees, the sheriff’s office said in a statement cited by CBS News. Allen also shot and wounded Lewis Mabrey Jr., another of Pritchett’s employees. Mabrey is listed in good condition.

According to authorities, Allen then returned to his home in Lake Butler where he shot and killed himself. They have released no information about a possible motive.