Another thingChris knew he had to assemble the gunso he knocks on that woman's door, she lets him inwhere and how did he figure to assemble and load the gunwhile the woman patiently watches him do it? But Allen has her conveniently go into the bathroom, giving Chris the time. Absurd.

I suspect the police would have been perfectly happy to write it off as a drug crime rather than try to pursue the member of a wealthy family and risk having a huge egg on their face.

I know.. This is exactly what I thought ! This crime has chris name written all over . He was everywhere in nola's diary and I bet she wrote everything in there , chris father in law has the same type of shotgun used in the crime! What other damn evidence do they need to accuse him for murdering her .. Is like nola said in that dream it was like he was begging to be discovered and punished , because he couldnt handle all the guilt .but well he was "lucky"

The plot holes as far as I see them

1. The sound of the shotgun - why didn't the neighbor who stopped by later hear the initial gunshot.
2. Nola called her agent and broke an appointment. She also talked to Chris on the phone in front of a co-worker.
3. There is the issue with the pregnancy.
4. Or if she wasn't pregnant, I find it incredible that she didn't discuss her plan to some extent with her diary. In this case, yes, she does know it isn't true and may not explicitly state "I told him I am pregnant but I'm not," but she probably detailed the interactions she used ("I'll be showing soon"), his reactions, her bewilderment, the fact that she wanted him to leave his wife.
   If Chris's name is all over her diary, as the cop says, it surely would involve this. She's not going to talk around it.

I mean how can police still be not sure that Wilton's the killer after having found out that Chloe's father has those type of rifles.
It all comes down to motive, fate and luck.
We assume Chris has no prior convictions. The police know that he was involved with Nola, but they genuinely feel the evidence points to a drug-related crime.
The police would have to have really strong evidence to seek warrants to head out to the Hewett estate to confiscate all the shotguns out there.
They don't have that evidence and then the ring-finding junkie is found dead.
Case closed!

there is 0% gun violence in Britain, and should there happen to be one incident in ten years, it gets dealt with most harshly
Huh?
I live both in the US and UK. And with 50 quid and a bus trip from my home in SW7, without even changing buses once, I could buy any gun made if you know where to go east of Aldwych or south of Bermondsey.
What in the hell is old Piers talking about? What a dope.
Outlawing guns in Britain after Dunblane only put the very lucrative illegal gun trade into the hands of the gun runner Romanian, Russian, Albanian and Latvian crime gangs that are more populous in Greater London now than fleas on a dog.
And god KNOWS what goes on in Tower Hamlets these days. But most of us don't know because nobody goes there anymore if you aren't a follower of Islam or you might get beat up on the street in that populous carbon copy of downtown Baghdad. So if there are guns there, only the locals know about it.

The only thing they can deduce is that it was a shotgun, and maybe the gauge type (12 gauge, 20 gauge, etc.) MAYBE even the barrel length as well. He could have been using a tactical, custom, police shotgun for all they know.
And, as you saw, that thing was so easy and quick to assemble and disassemble. It easily fits into a bag. It made a fine weapon for being "discreet" that is easy enough to tote around.

They knew they had motive - even mentioned how motive alone won't make the case.
As people have pointed out, the whole point was that he got really lucky and, at least in the eyes of the law, got away with it.

Yeah nola's co worker may be interrogated and tell what she knew about nola and chris .. Another point to accuse chris For the crime.

First, I agree that if Chris' name was all over the diary, there should have been some mention of the pregnancy. Afterall, they were aware that he had prmised t leave his wife for her. (NOTE: I reject the notion, as some other threads have suggested, that she faked her pregnancy. The movie would have eluded t that in someway either before or after her death)
Secondly, as Chris was planning Nola's murder he had the conversation with her to find out if anyone else knew about them. She lead him to believe that she had not discussed it with anyonehowever, in the scene where Chris called Nola's job to tell her she needed to come straight home after work, Nola's co-worker seemed to be very aware of Nola and Chris' affair. What was the point in bringing that out in the movie if it was not going to be explored or to serve as a plot point?
Lastly, although Chris exhibited all of the classic behavior of a cheating spouse, aside from a passing inquiry, his wife never suspected he was being unfaithful. Sure, I get that he was a businessman and would occassionally get calls that he would need to take privately, but, the number of calls he took "privately", his change in demeanor after each call and his sudden downturn in his work pewrformance, should have at least given Chloe, Tom or the father pause to be concerned that something was not right.
Anybody else feel me on these points?

I agree!! If the detectives found Chris's name "all over it" then surely Nola would have written the most important fact about their whole affair. Unless, as we talked about on another thread, she was lying about being pregnant. There'd be no reason to write it in there because she would obviously know it was a lie.
A bigger plot hole for me was that there was gun violence in Britain at all, and Scotland Yard didn't swoop in and do their best Sherlock Holmes! According to Piers Morgan, since guns are outlawed there, there is 0% gun violence in Britain, and should there happen to be one incident in ten years, it gets dealt with most harshly.
(I already see the flaw in my theoryusing Piers Morgan as a reference for anything I should have stopped writing long ago)

The biggest plot hole for me was that her diary would surely have mentioned she was pregnant which would have given the detectives the motive for him killing her.
All those moments will be lost in time, like tears in rain. Time to die.

You are implying that burglars are smart.
That's your first mistake.

Doesn't matter a single bit. Spend a day in a major metropolitan police investigation. As soon as that suspect was found with a stolen ringeverybody is going to take the easy exitregardless of of loose ends people take the easy route.

When he put the gun back in the rack, he also put some empty shotgun shells into the carrying case hanging on the wall. So even if the gun still smelled of gunpowder, they would assume it hadn't been cleaned after hunting, because of the empty shells nearby.

The shotgun was considerably shorter than the two on either side of it when he put it back in the cabinet. I'm thinking it may have been used by one of the women to hunt small birds and game.
I doubt Chris had time (or foresight) enough to clean the shotgun before placing it back in the gun cabinet, so the police could have determined it was recently fired, even if they couldn't prove it was the actual gun.
But as another poster said, once the police found the ring with the drug addict, it was off to the pub, case closed.

The detective on the scene specifically mentioned that the shotgun was probably sawed-off, easy to conceal and that a lot of criminals use that kind of weapon. Of course, he was wrong about it being sawed-off, but the conclusion was made.

It wasn't a rifle, it was a shotgun. As far as I know, it's not possible to match shotgun pellets with the gun they were fired from, in the same way that bullets from a pistol or rifle can be matched. So the evidence that Chris had access to firearms was presumably only circumstantial and would not hold much weight in a trial.

You're wrong; the detective's last question was if he owned or had access to guns and he told them his father in law has rifles on the estate. The detective also thought that was a reason worth pursuing him as a suspect even further; remember, it wasn't until the next day, when the other burglar was caught with the ring, that they finally ruled Chris out as a suspect and considered the case closed.

I understand that, what Im saying is that even before the police found out about the burglar with the ring, they were still not sure if Chris did it or not even though they knew about the rifles.

Chris could have written his name all over the apartment and it wouldn't have mattered.
That's the whole point of the movie; luck is the most important thing.