Jimmie first appears after being hired by Phil Mitchell to represent Jane Beale in her divorce hearing with Ian Beale. In November, he is hired again to help Phil's cousin Roxy Mitchell regain custody of her daughter Amy from the father, Jack Branning. He suggests that Roxy dig up as much dirt on Jack and his family as she can. Roxy does this, deciding to use Jack's brother Derek Branning's criminal past against Jack, as Derek is staying with him, but this fails and a court grants custody of Amy to Jack. Phil then sacks Jimmie, though his relative Billy Mitchell asks Jimmie for advice on his pregnant granddaughter, Lola Pearce, whose baby Lexi could be taken into care once she is born. Jimmie advises Billy to apply for a Special Guardianship Order, which would grant him legal responsibility for the child.
He returns on 9 February 2012 at Amy's custody case, after which Roxy gains custody of her. On 23 October 2012, Jimmie speaks to Phil about gaining custody of his grandchild and Lola's baby Lexi, as she has been taken into care. Jimmie says that Phil would have a better chance of gaining custody if he is in a stable relationship. Jimmie later tells Phil that his son Ben Mitchell's murder charge has been dropped and he will be tried for manslaughter, and that Ben has agreed to a visit from Phil. When Jimmie advises Phil that he needs to find a way to prove to the court that he has a good support network for Lexi, Phil secretly orders Jimmie to put Sharon Rickman's name down on the application as his fiancée and Jimmie helps Phil to become Lexi's guardian, while Lola is allowed three access visits a week but at another court hearing, Phil tells the court that he can't think of a better mother for his granddaughter.