A police officer who leads a search of Phil Mitchell's properties—his home, The Queen Victoria and Mitchell's Autos—in a dawn raid. Kain does not say what they are looking for but leaves empty handed, saying they will be back. Kain later returns to tell Phil they have recovered several items of stolen jewellery buried at the local allotments. Kain later arrests Billy Mitchell, as they found his fingerprints on the stolen goods.
In June 2012, Kain questions Michael Moon about an allegation of fraud, and releases Michael on police bail.
He returns in 2013, credited as DS Bain, and speaks to Bianca Butcher about the mugging of Tamwar Masood, as her son Liam Butcher may be involved. Bianca gives Bain a false alibi for Liam. After Liam and the gang he is involved with are arrested, Bain and his colleague DC Booth interview Liam about his involvement with the gang. Bain offers help as long as Liam is honest with them.
After Liam is stabbed by a gang member, Chris, Bain tells Liam that Chris has been arrested, but tells Bianca that he has not been charged as the gang all denied any involvement and there is a lack of evidence.[
In June 2014, Bain appears when he investigates an assault on Sharon Rickman during a break-in at her Wine Bar, The Albert. Bain questions Sharon as she is recovering in hospital and she is unable to give him a description of her attackers. Phil, who is Sharon's partner, tells Bain to leave as he is distressing her. Bain does so after giving Sharon his card.
In January 2015, Bain arrests Phil for criminal damage with intent to endanger life by cutting the brakes of his cousin, Roxy Mitchell's car.