PORT-AU-PRINCE, Haiti—Haiti’s National Police said Saturday that a former senator who is a prominent suspect in the July 7 killing of President Jovenel Moïse has been arrested in Jamaica. Police spokesman Gary Desrosiers told The Associated Press that John Joël Joseph was in custody. No further information was immediately available. Meanwhile, Jamaica Police Superintendent Stephanie Lindsay told the AP that other people were arrested along with Joseph and that authorities were trying to determine whether they are family members. She said they were arrested before dawn on Saturday and declined to share other details. “For more than one reason, we’re not sharing more information,” she said. Joseph is a Haitian politician and opponent of the Tet Kale party that Moïse belonged to. “One more suspect has been apprehended. One more opportunity to shed light on my husband’s murder,” wrote Martine Moïse, who was injured in the shooting, on Twitter. “In …