A police officer had probable cause to believe that a defendant was involved in a robbery. The officer obtained a valid arrest warrant and went to the defendant's apartment to execute it. The officer decided to go to the defendant's apartment right when he believed the defendant would be home from work, so he could search the defendant's apartment before he had a chance to hide the stolen goods. When the officer arrived at the defendant's apartment, the door was ajar, but nothing else seemed out of the ordinary. The officer slowly opened the door and entered the apartment. He walked toward the back of the apartment, and when he heard the defendant in a bedroom, pushed open the door, loudly told the defendant to freeze, and arrested him. Did the officer properly execute the arrest warrant