A priest will also have a person go under certain tests to see how they react. This may include seeing their reaction when entering a Church where the Blessed Sacrament is present. "One would be the rolling of the eyes, and that's usually because of an aversion to the sacred. So if someone was to walk into a church or even the parish center...and they cannot stand to look at the crucifix. Or...walk into a church and cannot stay or can only stay with great difficulty because of the presence of the Eucharist or a crucifix or another sacramental, or a statue of the Blessed Mother" explains Father Gary Thomas, a renowned exorcist within the Catholic Church (qtd. in Coffin). Other tests and signs may include the aggressive movement of arms or legs in an intimidating manner (Coffin). Another sign may be a wide yawn during a prayer which is "a criterion of possession dating to 1614 (Burke).