Sheridan, meanwhile, begins again her claims that Marty is her son and not Beth's. A DNA test is eventually performed, and the results come back showing Beth, not Sheridan, to be Marty's mother. Despite the results, Sheridan continues to claim Marty as her own, but Luis, faced with DNA evidence, sides with Beth. Eventually, it is discovered that Alistair had fathered Beth, making Sheridan and Beth half-sisters — the DNA test had only examined Beth for kinship, not for maternity. Luis and Sheridan set off to reclaim Marty, but Beth flees with the boy; when they catch her at a cabin in the mountains, Luis is unable to shoot her, allowing Beth to escape the country with Marty. Sheridan is furious with Luis for his inability to believe her and ends their relationship. Luis is wracked with guilt and leaves Harmony to search for Marty; at the time, actor Galen Gering and NBC had become engaged in a contract dispute that had nearly caused Gering to leave "Passions". Although he eventually re-signed, the writers had been forced to plan for Gering's possible exit and wrote Luis out of the scripts for over seven months. As a result, Luis makes only brief phone appearances in August 2005 before Sheridan and the Lopez-Fitzgeralds are told that Luis has been murdered in Tangier in October.