Four months after Jimmy Fowlie announced his sister Christina Lynn Downer went missing in Los Angeles, the comedian shared a devastating update. On Wednesday, the Saturday Night Live writer revealed that Downer is “no longer alive” and that the LAPD is now treating the case as a homicide investigation, instead of a missing persons case. “The LAPD has informed our family that Christina is no longer alive, and the case has officially transitioned from a missing person to a homicide investigation,” Fowlie wrote on Instagram . “Our prayers for her to be found safely have transformed into prayers for the truth to be revealed and for those responsible to be held accountable.” Fowlie explained that there is reason to believe Downer’s “phone and social media were compromised” in the weeks before she went missing. Watch on Deadline “The individuals in possession of her phone used it to hide the fact she was gone, to ask for money, and to create a false narrative that she was going ‘off the grid,'” he added.…