Suspect: Trystan Terrell (pictured), 22, has been charged with two counts of murder and four of attempted murder after Tuesday's University of North Carolina shooting

The college dropout gunman who opened fire on his old school on Tuesday, killing two people and injuring four others, smirked as he was led into the police station afterwards and proudly told reporters: 'I went into a classroom and shot some guys.'

Trystan Terrell, 22, was arrested at the University of North Carolina in Charlotte after running out of ammunition in a classroom where he had opened fire.

He killed two people and injured four but his motive for the shooting spree is unclear.

It began at 5.40pm when he burst into an anthropology class while students were giving presentations.

The victims were named on Wednesday morning as Riley Howell, 21, and Ellis Parlier, 19.

Drew Pescaro, 19, Sean Dehart, 20, Rami Alramatin, 20, and Emily Houpt, 23, were injured.

Terrell was a student at the college until this semester but dropped out. The circumstances around his departure are not yet known.

According to a 2016 blog post by his father, he is autistic. He had moved to North Carolina from Texas where he lived with his maternal grandfather.

His mother, Robyn, died from breast cancer in 2011.

Terrell has been charged with two counts of murder and four of attempted murder.

He also faces four charges of assault with a deadly weapon and two for alleged firearms offences.

A video taken as he made his way into the police station on Tuesday showed him turning to answer a reporter who asked what happened and saying without a hint of remorse: 'I went into a classroom and shot some guys.'

He is due in court on Thursday afternoon.

Trystan Terrell, the 22-year-old suspect in the shooting at the University of North Carolina at Charlotte on Tuesday, was seen smirking as he was led into the police station during his arrest

Terrell is shown with his sister and father in a photograph that was uploaded to social media two weeks ago

He opened fire in a classroom with a handgun, according to witnesses.

He shot until he ran out of bullets, they said, and then was taken into custody.

Terrell grew up in Arlington, Texas, but moved to Charlotte two years ago to live with his father.

His grandfather reacted in shock to the news on Tuesday and said he never showed any interest in guns or weapons.

Riley Howell, 21, died on Tuesday in his classroom in UNC. He died 'jumping' on the gunman to try to save others, according to witnesses

Drew Pescaro (left) and Emily Houpt (right) were both injured but will make a full recovery

Video posted on social media from moments earlier shows police taking Terrell, the suspected gunman, into custody in Charlotte on Tuesday

The gunman shot dead two people and wounded four others on the campus of the University of North Carolina at Charlotte

Rold told The Associated Press that the actions don’t sound like his grandson.

He said: 'You're describing someone foreign to me. This is not in his DNA.'

He added that Trystan had never shown any interest in guns or weapons and claimed he taught himself French and Portuguese.

But classmates described him as 'quiet' and introverted.

'He just seemed really quiet and standoffish.

'I've never seen him talk to anyone else or socializing really like the rest of the people around campus, because we're pretty close-knit.

'Everyone knows everyone pretty much and I've never seen him at events or parties or anything like that,' one told Fox 46.

According to an eyewitness, Terrell burst into a classroom with other students when he decided to open fire.

'There was an active shooter in my room in the Kennedy building at UNC Charlotte, get to safety immediately,' Tristan Field, a student at the Charlotte campus, tweeted on Tuesday.

'Why would anyone do this. We were just doing presentations and someone started shooting up the room.

'We didn't do anything but our work. Stay safe UNCC..'

Field added: 'The shooter at UNCC didn't say anything. He just started shooting during our final presentations and we all ran out.

'I'm praying for everyone that got hit and UNC Charlotte as a whole.

'Why here? Why today? Why UNC Charlotte? Why my classroom? What did we do?'

Authorities later said that there were three people in critical condition.

The Alpha Tau Omega fraternity posted a tweet saying one of its members, Drew Pescaro, was wounded in the shooting.

'We support the students and personnel at UNC-Charlotte affected by today’s tragic shooting,' ATO's national office tweeted on Tuesday.

'ATO brother Drew Pescaro was shot and is currently hospitalized in stable condition. We are keeping Drew, the chapter and the campus in our prayers.'

Students posted images on social media showing themselves during the lock down.

One of the gunshot victims is seen in the above photo being helped by another person

A blood stained shirt is seen above after a shooting at the University of North Carolina at Charlotte on Tuesday

The image above shows students at UNCC remaining in place after news about the shooting broke

Shattered glass is seen on the floor at the entrance to a building on campus in Charlotte on Tuesday

The school's official Twitter handle tweeted alerts to students and faculty

On Tuesday night, the university's chancellor released a statement to say it had been the 'saddest' day in its history.

'This is the saddest day in UNC Charlotte’s history. Earlier this evening, the unthinkable happened on our campus.

'Families of the deceased victims are being notified, and university staff are with those who are injured. The entire UNC Charlotte community shares the shock and grief of this senseless, devastating act. This was an attack on all of Niner Nation,' he said.

Finals that had been scheduled to take place on Wednesday are now due to happen on Sunday.

Dramatic video posted on social media shows students the Charlotte campus being evacuated after the shooting.

Uniformed police officers were seen running toward the location of the shooting while panicked students fled in the opposite direction, some with hands up.

A helicopter was also seen flying overhead during the tense moments.

One video posted to social media shows a large group of students with their hands up in the air

The campus was to host a concert at the school’s football stadium to mark the last day of classes

The campus was to host a concert at the school’s football stadium to mark the last day of classes.

Students were on their way to Jerry Richardson Stadium to see the rapper Waka Flocka Flame.

'I'm safe y'all,' the rapper tweeted on Tuesday.

The university has more than 26,500 students and 3,000 faculty and staff.

Sam Rice, a senior on UNC Charlotte's tennis team, told Spectrum News that he was in the library studying for a final exam when he heard people yelling 'shooter, shooter.'

He said he heard police yelling for people to stay down and stay on the floor.

Students were on their way to a campus stadium for a scheduled concert by rapper Waka Flocka Flame (seen in the above stock image)

The rapper tweeted on Tuesday: 'I'm safe y'all' (seen above)

He was 'waiting for someone to tell us everything was going to be OK.'

When people were told to leave, he ran out in his socks, running over glass on the floor.

His reaction is 'just shock,' he told the television station. 'It doesn't feel real.'

Susan Harden, an UNCC professor and Mecklenburg County Commissioner, was at home when she heard of the shooting.

She went to a staging area, she said, to provide support.

Harden said she has taught inside the Kennedy building, where the shootings occurred.

'It breaks my heart. We’re torn up about what’s happened,' Harden said.

People gathered across from the campus of UNC Charlotte on Tuesday moments after the shooting

Law enforcement officials secure the main entrance to UNC Charlotte on Tuesday evening

'Students should be able to learn in peace and in safety and professors ought to be able to do their jobs in safety.'

Charlotte's mayor, Vi Lyles, tweeted: 'We are in shock to learn of an active shooter situation on the campus of UNC Charlotte.

'My thoughts are with the families of those who lost their lives, those injured, the entire UNCC community and the courageous first responders who sprang into action to help others.'

U.S. House Rep. Mark Walker, a Republican from North Carolina, tweeted: 'Absolutely heartbroken to learn of the two deaths at UNC-Charlotte.

'Details still unfolding, but prayers with those receiving medical care right now.'

Concerned students gather on campus after the shooting on Tuesday afternoon

A UNC Charlotte campus police officer carries a tactical shield after the shooting on Tuesday

A number of emergency vehicles are seen on Mary Alexander Road on the UNC Charlotte campus on Tuesday

U.S. Senator Thom Tillis said on Twitter: 'Absolutely horrific news at #UNCC Susan and I are grateful for the first responders at the scene and our thoughts are with the @unccharlotte community.'

Said Rep. Richard Hudson on Twitter: 'Renee & I are heartbroken to see violence at my alma mater @unccharlotte.

'Grateful for the quick action of 1st responders & police.

'Our prayers are with victims, their families & the #49er community.

'I’ll continue to monitor the situation & pray for the safety of our campus #UNCC.'

North Carolina's governor, Roy Cooper, tweeted: 'This is a tragic day for Charlotte and this great university.

Gabrielle Giffords, the former Arizona congresswoman who was shot in the head and wounded in an assassination attempt in January 2011, tweeted: 'I am so sorry for these young people and their families. We fail as a nation when we fail to protect our children. You deserve better.'

'We mourn the lives lost and we will all be here to support each other.

'I commend the first responders for their quick action and am grateful that the campus is now secure.'

Gabrielle Giffords, the former Arizona congresswoman who was shot in the head and wounded in an assassination attempt in January 2011, tweeted: 'I am so sorry for these young people and their families.

'We fail as a nation when we fail to protect our children. You deserve better.'

Since the shooting, Giffords has become an advocate for gun control legislation.