The medical examiner determined that Christa died from a single stab wound to the heart. Defensive wounds on her body, such as trauma to the head and abrasions to the arms and legs, also indicated a struggle. Most importantly, there was clear evidence that Christa had sexual intercourse before her death. Investigators collected DNA samples from her body hoping to find out the identity of her killer. Michael Iacuessa of the Provincetown Banner stated in an article that several items were missing from her house, including a wireless Panasonic phone, ID and credit cards. Her purse and car keys were found in the driveway.
It is not clear if Ava witnessed the murder or was elsewhere in the house when it happened. What is certain is that she was on her own for around 24-36 hours, the length of time between Christa's death and the discovery of her body. During that time, the 2 1/2 year-old was able to sustain herself by suckling from her mother's corpse and eating cereal, which she found in the cupboard, Harriet Ryan wrote in a Court TV article. Ryan also said that at some point, Ava, too young to understand her mother's condition, "tried to revive her mother with a drink from her sippy cup."
Realizing that there was little evidence to work on, investigators began interviewing those who knew Christa hoping to find new information that might provide more insight into her death. The police were especially interested in conducting interviews with Elizabeth Porter (the mistress of Christa's father), Tony Jackett and Tim Arnold. What investigators discovered was a series of complex relationships that put some of the individuals in a more questionable light.
Cape Cod District Attorney Michael O'Keefe was quoted in Maria Flook's book "Invisible Eden: A Story of Love and Murder on Cape Cod," as saying that Christa was "an equal opportunity employer. She'd (expletive) the husbands of her female friends. The butcher or the banker." The remark outraged Christa's family. Nonetheless, it became increasingly clear that there were a lot of people who knew Christa that could have had motive to kill her. Whether any of them actually did was another question, one that the police had yet to answer.