The boyfriend of the sorority girl allegedly murdered by an active duty Marine in a road rage attack on New Year's morning has told how he is surviving, 'day by day'.

Speaking exclusively to Daily Mail Online Brice Riddell, 20, who had dated Sara Mutschlechner since mid-summer spoke of his devastation at how life can 'just be gone in a moment' and revealed his heartfelt hope that justice will be done for his 'sweet sweet girl.'

Standing in front of his fraternity home in Denton, Texas, the University of North Texas student said: 'We were together at least midway through the summer until New Year.

'It's day by day right now. We're all getting stronger in remembrance for all the great times we had with Sara.

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Grief: Brice Riddell, 20, had dated Sara Mutschlechner since mid-summer. He spoke of his devastation at how life can 'just be gone in a moment' and revealed his hope that justice will be done for his 'sweet sweet girl'.

Pictured: Cpl Eric Jamal Johnson, 20, (left) has been arrested on suspicion of shooting dead sorority sister Sara Mutschlechner (right), a 20-year-old University of North Texas junior, early on New Year's Day

Pictured: Cpl Eric Johnson, was arrested at his air base in Yuma, Arizona, on Tuesday morning. He is an administrative specialist of Marine Aviation Weapons and Tactics Squadron-1, which he joined in August 2013

'There was a very nice vigil that happened in the Greek Life office. I'm drawing strength from all the brothers and friends and just hanging out and having good times because that's what Sara would have wanted.'

Twenty-year-old Sara's last tweet was a reference to the time she had spent with Brice earlier on that fateful New Year's Eve night and Brice recalled: 'I was with her all the way up until about an hour before everything transpired.

'It's just crazy to imagine how everything can just be gone in a moment.'

Brice had partied with Sara and friends at the now infamous gathering on Crisoforo Drive until around 1 in the morning when he left, bidding her a Happy New Year.

Now, trying to make sense of the violence that followed barely an hour later Brice said: 'I don't know if it was out of hate, out of just wanting to make a point more than they even intended but the issue is it happened and it's not okay.

'I'm just really relieved that they've finally found somebody who's directly related to what happened. She was such a sweet, sweet girl.

'She deserves justice.'

Cpl Eric Johnson, of Marine Aviation Weapons and Tactics Squadron-1, was arrested at his air base in Yuma, Arizona, on Tuesday morning.

According to police, shots were fired from a black SUV that pulled up beside Sara as she was driving through Denton, Texas, in the early hours of New Year's Day.

Johnson, 20, is an administrative specialist and had been stationed at the Marine Corp Air Station in Yuma since August 12, 2013. It is unclear if he was on holiday leave.

He will be detained in Yuma County Jail until he is extradited to Texas.

Johnson was at the same party as Sara and her friends. He left at around the same time with two of the party's performers of the rap collective Dayonta Boyz, as well as two other African American males in a black SUV

Mutschlechner, philanthropy chair of her sisterhood, was driving this sedan when she got into a fight with members of an SUV. Shots were fired, she was hit in the head, then crashed into an electrical pole

Sara's group had been at a nearby party on Crisoforo Drive which hosted a number of musicians, including local rap collective The Daytona Boyz. They left shortly before 2am.

Johnson, whose street name is 'Santana Sage', was also at the party. He left at around the same time with two of the Dayonta Boyz - known as Tay-K and F***PimpyZ - and two other African American males in a black SUV.

Both vehicles were driving through Denton when Johnson's black SUV pulled up alongside Sara's sedan.

Members of Johnson's group started shouting that they wanted to 'f***' the two girls in the car.

One of Sara's two male friends hit back that the comments were inappropriate. One of the men in the SUV told him he would 'beat his ass' and another said, 'I'll shoot your ass', and 'displayed a handgun'.

According to police, Sara's party did not make derogatory comments in response and drove off.

But as they went through the intersection at West University Drive, shots were fired from the SUV and Sara was hit in the head.

The 20-year-old immediately lost control of her sedan, veered to the right into a parked car then crashed into an electrical pole.

She was taken to hospital and treated for her wounds but died later on New Year's Day.

Another girl in Sara's car broke her collar bone, and was treated in a local hospital.

Police said at least two of the men in the SUV had been at the same party as Sara and her three friends but the groups are not believed to have interacted until the dispute between their vehicles.

They insisted that the investigation is ongoing. Detectives are examining surveillance film taken from a nearby business, which is believed to show the vehicle involved.

Speaking to Daily Mail Online Johnson's stepfather, Darryl Joseph, 49, expressed shock at the news of Johnson's arrest which he said he was only just learning. He said: 'Eric's a great kid. He's never had no problems.'

The house on Crisoforo Drive where Sara had partied with her friends was empty yesterday after the occupants who rented the house left in haste, clearing out their stuff and piling it into a truck just yesterday.

Outside the evidence of the party was clear with overstuffed trashcans and bags holding beer cases, cups and other party detritus.

Neighbors said the occupants who rented the house left in haste, clearing their stuff into a truck just yesterday

Today the house on Crisoforo Drive where Sara partied with friends lay empty, its door wide open

Respectable: Eric Johnson's family home in Fort Worth, Texas. He lived on based with the Marines

This was the flier made for the New Year's Eve party Sara and her friends attended, as well as Johnson and his friends, including at least two members of headline act Daytona Boyz, Tay-K and F***PimpyZ

According to police, Johnson (pictured left and right) threatened one of Sara's male friends and flashed a gun

Johnson (pictured, left, with a friend). Sara's friends who were in the car with her have told police they recognized this 'F*** Everybody' shirt, and said someone in Johnson's car was wearing it during the fight

In the car with Johnson: Police said two members of the rap collective the Daytona Boyz were also in the black SUV. They identified the rappers by their stage names: F***PimpyZ (left) and Tay-K (right)

The police were called at least twice as the party raged on Thursday night and into the small hours of Friday morning with one neighbor reporting partygoers banging on her door and windows at 5 in the morning.

According to Mallory Bersi, 21, 'It was really weird. At like 5am someone was banging on the door trying to get into our house. They were like banging on the door, on the windows, they went into the back yard. We called the cops. Things like this don't happen in this neighborhood. It was crazy, scary.'

A neighbor of Eric Johnson's mother Sheryl Joseph, Virgil Turner, 49, has lived across from them for six to eight years.

'When we got here they were already here. I know Eric a little bit. When we moved here him and my kid used to play. They used to skateboard up and down this street. Then he took off and went to the military.

'He was a nice boy. I'm very surprised.

'I know his mom. She's a very nice lady, very friendly, never had a problem with her.'

He added: 'I'm just shaking with this news. I'm very surprised. He was a very nice boy from a very nice family.

'I haven' t seen him but he was back here for the weekend.'

According to her LinkedIn page, Mutschlechner had volunteered at the American Cancer Society

The parents (pictured) of Mutschlechner said their daughter had dreamed of being a film director or producer and that being an organ donor was a cause close to her heart

Mutschlechner's devastated parents have revealed that she was an organ donor - and that she has already helped a burns victim.

In an interview with Fox 4, the parents of Mutschlechner said their daughter - a junior at the University of North Texas - had dreamed of being a film director or producer and that being an organ donor was a cause close to her heart.

Her father Clay called the killing 'senseless and tragic' while her mother Gloria said: 'All I could think about was her and this horrible thing that happened to her. She did not deserve this.'

Clay added: 'We're all going to miss her. Some people don't get to have their kids 20 years. We have to be blessed with what we've had with our time spent.'