"Looking back on it, I don't know why - why I did things how I did,'' said Entwistle.”Once I kind of realized what happened ... you think in those situations I would just look and break down, but that's not what went through my head. Well, the first thing I wanted to do was to do something to myself.'''
Neil Entwistle speaking about finding his wife and child bodies to Sergeant Robert Manning of Massachusetts State police. The Telegraph, 21 June 2008
His wife and child were dead and Neil Entwistle was nowhere to be found. Initially, Neil is not a suspect, just a person of interest. This quickly changes as the police investigation gains momentum.
Detective Sgt. Robert Manning is the lead officer investigating the case for Massachusetts police. Finding Neil is missing, he phones the Entwistle’s home in Nottingham. It proves to be an odd telephone call. During the conversation, which is later played at his trial, the police ask Entwistle for his version of events surrounding the deaths. He explains how he returned from doing chores around 11am on the 20 January and found his wife and child dead in their home. He maintains he no idea who has killed them. His first thought was to kill himself. In a confusing move, he neglects to call police for help.
During the phone call, Entwistle tells police how unable to kill himself with a knife, he seeks a gun at his in-laws house. Intrigued by this disclosure, the police speak with his step-father, Joe Materazzo, who confirms they have taught Neil to shoot their Colt .22 handgun. The investigation makes a breakthrough discovery, the gun found at in-laws house is the murder weapon. Forensic tests reveal that Neil’s fingerprints are on the gun.
The investigation looks into Entwistle’s personal circumstances and finds he is unemployed and has been since 2005 plus he has racked up has $30,000 of credit card debt. Authorities suspect there could be a financial motivation for the killings. Even more concerning to the police were his recent activities online: a search of Entwistle's computer reveals that days before the murders, he looked at a website that described "how to kill people" and escort services.
Establishing links being between Entwistle and the murder weapon plus his poor finances and promiscuous behaviour are casting doubt on Entwistle claim of a perfect family life. The police decide they have the enough evidence to build a case against Enwtistle for the double murder of Rachel and Lillian.