The person believed responsible for an attack targeting a Palm Springs fertility clinic Saturday posted rambling online writings before an explosion that investigators are treating as an act of terrorism, a law enforcement official told The Associated Press.

An explosion outside a fertility clinic in Palm Springs, California on Saturday resulted in one fatality and four injuries, in what authorities are describing as an “intentional act of terrorism.” Pal

The FBI identified a person of interest in an explosion that killed one and injured four near the American Reproductive Centers in Palm Springs.