ARLINGTON — Hours after the Rev. Clint Dobson was suffocated with a plastic bag and his assistant severely beaten inside NorthPointe Baptist Church, the suspects in his slaying laughed while watching a television news report about the case, according to court documents. Steven Lawayne Nelson, 24, and Anthony Gregory Springs, 19, “began laughing and making inappropriate comments about Dobson’s death” Thursday, according to the arrest warrant affidavit for Nelson. “When confronted about this behavior, [Springs] produced an item he claimed belonged to Dobson.” The boasting that evening at a friend’s house was a turning point in the fast-moving investigation into...