A second police officer who defended the Capitol during the siege on Jan. 6 has died by suicide, the acting chief of the Metropolitan Police Department told Congress this week. Chief Robert J. Contee III told a House committee that Officer Jeffrey Smith, a 12-year veteran of his department, had killed himself on Jan. 15 and that Officer Howard Liebengood, a 15-year veteran of the Capitol Police, had also died by suicide days after the attack. The Police Department declined to give a cause for Officer Smith’s death or say whether it was connected to the riot. His family could...