EXCLUSIVE - Best friend, business partner and suspect: Man who was last to see McStay father alive breaks silence to reveal new clues in mystery murder of family who vanished

• Chase Merritt, 56, has been accused of having a hand in the disappearance nearly four years ago of the McStay family
• Broke his silence with MailOnline after family's remains were found in a shallow grave in the desert last Friday
• Says he voluntarily took a lie detector test when family left their home in a hurry in 2010
• Husband Joseph McStay called his phone at 8.28pm that night but Merritt bitterly regrets not answering because he was watching a film
• Claims wife Summer McStay was insanely jealous with 'one hell of a temper' but can't believe she played a role
• Believes there's no way the McStays would have wanted to move to Mexico 
• Says 'honest guy' Joseph would never have done deal with Mexican cartels
• Fully expects to be interviewed again by detectives after bodies were found

By Will Payne In San Bernardino County, California

Published: 20:20 EDT, 19 November 2013 | Updated: 06:26 EDT, 20 November 2013

He was the last person to see Joseph McStay alive, the last person Joseph called the day he went missing with his family and at one stage he was the prime suspect in their mysterious disappearance.

For nearly four years Joseph’s former business associate and best friend Chase Merritt, 56, has put up with accusations, gossip and outright lies, but has never said a word.

Now speaking exclusively to MailOnline – just a few miles from the secluded desert location where the remains of Joseph, wife Summer and their sons Gianni and Joey Jr where found last week - Mr Merritt has finally broken his silence.

I'm innocent! For nearly four years Joseph’s former business associate and best friend Chase Merritt has put up with accusations, gossip and outright lies, but has never said a word

In an explosive interview, the man with the greatest insight into the now notorious case, has told how: 

• He spent an hour-and-a-half with Joseph the day he vanished and spoke to him a further three or four times on the phone
• Joseph called him at 8.28pm the night he disappeared, but he didn’t answer, something he regrets to this day
• He was the one who first went round to the McStay’s house, realized they were missing and helped the family call the Sheriff
• He gave a lie detector test to police because they were convinced he knew where the McStays were
• He completely dismissed security footage showing the family apparently crossing the Mexican border, saying it definitely wasn’t them, because Joseph ‘walked like a duck’
• Joseph had no financial pressures - their business was doing better than ever and they had just landed a huge foreign contract
• He is convinced he will be hauled in for another round of questioning by detectives

Mystery: Merritt says he spent an hour-and-a-half with Joseph McStay on the day he disappeared with his wife Summer and children Gianni and Joseph Jr in 2010 from their home in Fallbrook. Merritt says Joseph was hugely excited and happy and gave no clues to trouble

Regrets: Merritt says he regrets not taking the last call from Joseph McStay - because he was watching a film and Joseph talked for a long time

The case of the McStay’s has gripped the nation, since they vanished without trace on February 4, 2010.

No one can explain how a seemingly normal suburban family who only moved into their new home in Fallbrook, California, three months earlier, could be living a regular life one day and then vanish the next. 

They took none of their belongings, left $100,000 in the bank and even abandoned their beloved dogs.

The case has sparked endless speculation, with both the police and amateur sleuths coming up with countless theories, some plausible, some wild and outrageous. 

When the McStay’s car was found in San Ysidro on the Mexican border four days after they were last seen and security footage of a family of four an hour later heading into the Central American country surfaced, the idea they had left of their own accord gained momentum. 

Then it emerged that the McStays had searched on their home computer about travelling to Mexico with children and learning Spanish.  

But even then rumors of dubious dealings with Mexican cartels bubbled away. And when four skeletal remains were found in shallow graves in the remote Mojave Desert, San Bernardino County last Friday, it put an end to any belief the McStays had started a new life in the sunshine.

That is something Mr Merritt – who is now designing gold prospecting equipment - says he knew from the start. The talented welder met Joseph three years before his disappearance and went into business with him.

He made sought-after bespoke fountains, a product Joseph sold through his company Earth Inspired Products and before long they were working almost exclusively with each other, forming a very close friendship in the process.

Murder: The discovery of the family's skeletal remains last week in a shallow grave in the California desert has reignited countless theories of what happened to the McStays

Speculation: Merritt's criminal background and the fact he was the last to speak to Merritt have made him a target for accusations but Joseph's wife Summer has also been suspected as have Mexican drug cartels

Merritt claims he is uniquely positioned to put to bed some myths around the case and throw up some interesting clues as to what really happened to the McStays.

'There's no way Joseph would have taken his children to live in Mexico'

‘I told the detective back in the very beginning, that there is absolutely no way Joseph would have left without telling me’, Mr Merritt said, talking to MailOnline from a restaurant, in a remote spot near where he has moved since the McStay’s disappearance.

‘He was my best friend and we told each other everything. When they (the police) showed me the video of them crossing into Mexico, I told the them Joseph would not go into Mexico with those kids and that the man in the footage was not him. 

‘Joseph had a very particular walk, it sounds strange, but he moved like a duck and that man didn’t. There is absolutely no possibility that was him.

‘He used to make regular surfing trips to Mexico with his buddies, but actually stopped a few years before he disappeared because the country was becoming too dangerous. There’s no way he would have taken the kids there.

‘And any suggestion he was involved with the cartels is nonsense. Joseph was the most honest person I had ever met. I crossed his Is and crossed his Ts. He wouldn’t even drop litter, let alone get involved in anything more serious.

‘Even the thought of being involved in drugs would have sent him into a fit of paranoia. There’s no way he would have been caught up in crime, he was just not that kind of person.’

Nonsense: Merritt told police years ago that he never believed the family caught crossing the border, believed to have been the McStays, were them. He said Joseph 'walked like a duck' and the man in the footage didn't

He added: ‘I didn’t know Summer was learning Spanish, but I did know she had had tried to learn French and Italian before. That’s what she was like, she went through little phases and fads. It would have been nothing more than that.’  

The last day: 'He was excited about life and how I regret not taking that last call'

As one of his closest friends and confidents, it was fitting that Mr Merritt was the last known person to see Joseph alive and the one who first discovered he was missing.

He said: ‘I was the last person Joseph saw. He came to Rancho Cucamonga on February 4 to talk to me about a huge business deal we had going on in Saudi Arabia.

‘We met for an hour-and-a-half for lunch. He was so excited. We had the Saudi Arabian project and a few other things going on. The business had never been so good and we were looking forward to the future. He did nothing to suggest there was anything wrong or untoward.

‘We both left and went home and I spoke to him on the phone about two or three times on his drive back to Fallbrook, all standard business stuff. The last time I spoke to him was around 6 o’clock.

‘It has been reported that I spoke to him in the evening, but that isn’t true. He did call me at 8.28pm, but I was watching a movie with my girlfriend, looked at the phone and decided not to answer. 

'When you talk to Joseph it takes about half an hour, so I thought I’d catch up with him in the morning. 

‘I didn’t answer that call and I regret it to this day.’ That was the last call made from Joseph’s phone. Around 40 minutes earlier a neighbor’s security camera caught what looked like the bottom of the family’s Isuzu Trooper pulling away from their home. 

But then there was nothing until the car was found, empty on the border.

'I wish I'd acted earlier': The seven day delay in telling police they were missing

Mr Merritt said: ‘Three or four days went by and I called Joseph several times a day, but couldn’t get hold of him. That was unheard of because we talked six or eight times a day. 

‘On the fourth day I drove out to his house, stopping at his mother’s on the way. I asked if she’d heard from him and she said she hadn’t. She called Mikey (Joseph's brother) and I suggested he meet me out there. I drove out, but Mikey didn’t call me. 

Grief: Joseph's brother Michael holds hands with his mother Susan Blake at a table with McStay's wife Erin in the middle during a press conference after the remains were found. Merritt reacted angrily to veiled accusations from Michael and Joseph's father, Patrick, that he had something to do with the disappearance

Family friend: Merritt said he contacted the family when he hadn't heard from Joseph and urged his brother Michael McStay and his mother Susan Blake to call the police after a few days

‘The family’s dogs were out in the backyard, so I gave them some water and food. I opened up a shed in the back for them to go in because it was cold and wet. 

'On the way back I stopped at his mother’s again and told her to get Mikey out there. 

‘It got to about the seventh day and I called his mom and said she should call the Sheriff. She did and they went out to do a routine check, but that was it.

‘Directly after that I told his mother ‘Tell Mikey, I don’t care what he’s doing, he needs to meet me out at his house’. This was on about February 11 and he came. 

‘We walked round the side of the house and found an open window. Mikey climbed in and opened the door for me, Mikey’s wife and his kids.’ 

Inside, the group found rotten eggs on the counter and no sign of anything having been packed away.

Mr Merritt said: ‘We asked all the neighbors, but nobody had seen anything.'

The Sheriff's department finally went to the house and realized something wasn’t right. That is when Mr Merritt – who has three children of his own – was contacted and questioned.

Mr Merritt said: 'They found the car about four days after they went missing, so who knows what they could have found if I’d have reported it straight away.

'I desperately regret that we didn’t tell the police sooner.'

A record for burglary, a lie detector test and an angry denial he's a 'crook'

Since Joseph – who was then 40 – disappeared with Summer, 43, Gianni, 4; and Joey Jr, 3, the finger of suspicion has been pointed squarely at Mr Merritt. 

It emerged he'd been on the wrong side of the law in his past, specifically a burglary conviction in 1978 and one for receiving stolen property nine years later. He served time in prison for both.

Hundreds of commenters on websites and blogs speculated that he was behind their disappearance, but more significantly detectives also viewed him very much as a person of interest.

But Mr Merritt hit back, saying: ‘Nine out of ten people on this planet have got some kind of criminal background. 

‘Mine is 25 and 30 years old now. I am 56, I am an old man. I got into trouble here and there when I was a kid, but I do not have some long criminal history, which is what people have tried to imply.

Love: Despite claiming that Summer had 'one hell of a temper', Merritt said Joseph clearly adored her and he can't believe that she'd have anything to do with their deaths

Danger: Merritt said claims that Summer and Joseph were planning to take their children, Joseph Jr, three (left) and Gianni, 4, (right) to Mexico are far-fetched. He said Joseph had stopped going to Mexico on surfing breaks because he said it was too dangerous

Why kill children? The crime is so shocking because the couple's beautiful children weren't spared the horror

‘I have worked for myself my entire life and there is no way you can go through your entire existence without annoying the odd person, I have, but I am not a crook.

‘I’m not the most perfect person in the world, I’ve made mistakes, I have even screwed people over a couple of times. I regret it, but that doesn’t give people the right to trash me, especially after I have lost my best friend.

‘Very soon after the disappearance, Lt Brugos who was leading the case, called me and asked if I would take a lie detector test, because he was convinced I knew where Joseph was. 

‘I declined at first and got some advice from an attorney, who told me not to do it, because if anything at all shows up they will harass you. 

‘But I spoke to my girlfriend about it extensively and decided, you know what, I’m just going to do the damn test, so they can forget about me and focus on something that might actually help find him.

‘About three of them came out to my attorney’s office in Palm Valley. They asked me whether I knew anything about the disappearance, and if I did know anything, would I tell them.

‘After I’d finished, Brugos’s partner said to me, "well there are a couple of inconsistencies" but that was just them trying to trick me into saying something. I didn’t hear any more about it after that.

‘Was I a suspect? Well, I don’t know if I’m the only one they asked to do a lie detector test, but I am the only one who actually agreed. They were certainly on my case.'

'What do they know?' Hitting back at McStay family suspicions

On Monday Joseph’s dad gave an interview stating he thought there were three prime suspects in the case, one of whom was a former business partner with a criminal history. 

Mr Merritt is not sure whether he is the man in question, but he dismissed the claims either way.

Doing well: The McStays had moved into this $320,000 just weeks before they vanished with $100,000 in the bank. Just months before they had supposedly been struggling to pay $800 a month in rent, sparking more theories. But Merritt said the McStay fountain business had taken off

The McStay family home was found with food on the counter and the pet dogs abandoned when police went to investigate in 2010

He said: ‘I don’t think his dad is talking about me because he has mentioned someone with an attempted murder charge and I have never done anything violent, I am the least violent man on the planet.    

‘Anyway I don’t think his dad knows much about all this. People have to remember, he lives in Texas and I knew the kind of relationship the two of them had. 

Summer McStay: Insanely jealous with 'one hell of a temper'... but not a killer

Jealous: Summer McStay didn’t like anybody from outside of the family taking up Joseph’s time and attention, Merritt said

Before the family’s bodies were discovered Summer came under suspicion because she went by a number of different aliases, had officially changed her name and lied about her age.

On top of that emails retrieved from the McStay family computer showed she sent Joseph vicious and almost threatening emails about his son from a previous relationship.

Mr Merritt says Summer was a flawed character, who was capable of blowing up and flying into a rage for the smallest of reasons. But he refuses to accept she was capable of any of the sinister allegations that have been leveled against her. 

Mr Merritt said: 'I knew Joseph as well as almost anybody. He told me things he didn’t tell anybody else, especially about his marriage.

'They were not the perfect couple, but then who is. Summer was a very jealous person and she didn’t like anybody from outside of the family taking up Joseph’s time and attention.

'He would often drive up to my house in Rancho Cucamonga and we would go to his favorite restaurant up there. 

'All through the meal he would be getting calls from Summer, he would try to ignore them and have a good time, but eventually he would have to break off and speak to her.

'And she had one hell of a temper. I remember once I went round to their house to fix Joseph’s washing machine. It got to mid- afternoon so I ordered some pizza for the family.

'Myself and Joseph sat down at one table and the boys sat at another separate one, where Summer had put out little plates with a slice on each and a knife and fork.

'I grabbed a slice with my hand and started eating. Summer went absolutely crazy she started swearing and cursing, saying I was teaching her children bad manners.

'I couldn’t believe it, but I just had to sit there and take it. Joseph didn’t say anything, he adored her and to a certain extent, he did what he was told. I knew their relationship and didn’t blame him.

'But despite all of that, they loved each other and I think it would be crazy to suggest Summer had something to do with all of this. After all what couples don’t have their problems.’

Still a mystery - even to his best friend

Mr Merritt says he couldn’t shed any light on the disappearance back in February 2010 and he still doesn’t know anything now that it is a murder enquiry.

He said: ‘Joseph was one of the nicest people on this planet. He was honest, he was gentle he was straight forward businesswise and he was generous. He would do anything for anyone. 

'I know for a fact he had nothing at all to do with anything illegal, he was honest as the day is long. I knew him as well as anybody, and Joseph had no enemies and no problems financially.

Friend: Merritt told MailOnline: ‘I may not be the nicest person in the world, but I have only ever had Joseph’s best interests at heart. That’s all I have ever cared about, despite what had been written about me'

‘We were in the middle of some of the best deals we had ever had. Financially we were doing very well. We had just started a huge project in Saudi Arabia worth $82,000 and right in the middle of that, Joseph disappeared. There was no reason for it.'

In answer to claims he may have got in over his head with drug gangs, Mr Merritt said: ‘His father said he had bought waterfalls from Mexico recently, but that wasn’t true, he hadn’t bought anything from there for two years because they were of inferior quality.’

Whatever really happened, one thing that is certain, is Mr Merritt seems genuine when he says he has lost a dear friend.

He said: ‘I may not be the nicest person in the world, but I have only ever had Joseph’s best interests at heart. That’s all I have ever cared about, despite what had been written about me.

‘I am a normal man, trying to take care of my three kids and I have lost a very good friend. I wasn’t Joseph’s best friend, but he was mine. I didn’t have many people close to me, but we shared a lot. He told me a lot of things he didn’t tell anyone else. 

‘Joseph’s family are the ones who lost the most from all this, no question. But financially I lost everything. I was manufacturing all the waterfalls he was selling and I lost my entire business. Without his sales, I had nothing. I went bankrupt very soon after he disappeared, It killed me financially. I even split up with the mother of my three kids because of the stress.

Justice: Merritt says he's talking now because ‘all I want is for them to find the a*******s who did this’

‘People may criticize me for speaking now. That’s their call, but I had a lot of opportunities to speak before and a lot of big money offers to do so.

‘At that time, I didn’t think anything I had to contribute would help to find Joseph and that was all I cared about. Anyway, I told the police everything I knew.

‘Now things have changed. It is not about finding them, it’s about finding the people who did this and if anything I say can help jog someone’s memory or offer some clue, then I’ll be happy.

‘I think the cops just accepted that they had crossed the border, because that was an easy option and they didn’t have any other kind of proof to lead them anywhere else.’

He added: ‘I don’t want to upset anyone, I just want people to know the truth. The McStay’s were not perfect like some people would have you believe, but they weren’t criminals or drug runners like others have said, they were just a normal family. Well, a normal family other than Joseph, who was the nicest man I have ever known.’

Finally he said: ‘I am convinced the police will be back in touch with me, I’m surprised they haven’t been already.  

'San Bernardino County have said they are going to start the investigation over from the beginning and if they do they’ll have to talk to me. But I will just tell them the same as I did the last time.

‘All I want is for them to find the a*******s who did this’.