Jack Harper

 was the owner of a record shop that Helen Sinclair was displaced in time to. He wanted to use the Weeping Angel and constructed something to inhibit him using the The Doctor's sonic screwdriver. He sent Trev Bailey back in time to deliver a letter. He was using the angel to scam people and get rare vinyls. He later sent Albie Sinclair back inside to get more information. He was killed by an angel. (AUDIO: Albie's Angels)