A Texas police officer has been fired after he was recorded on video threatening a teen and using profane language.

Disraeli Arnold, an officer in Hurst, Texas, was recorded in November running to assist an officer as he subdued a teenager, ultimately kneeing the teen in the back of the head while yelling and threatening him.

The teen's mother, Kelly Pope, didn't object to her son being arrested, just the force used to take the teen into custody.

"He [her son] knows that he handled it badly at first, that he should have been a little more cooperative. But, you know, the second officer -- there was no reason for it," Pope said in November. "He (Arnold) comes up at a jolting sprint, kneed him in the back of the head and, as you can see on the video, he says, 'If you move I'm going to [expletive] kill you.'"

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While the teen was in custody and being escorted to a police car, Arnold then paraded in front of the teen's friend, who was recording the arrest, and said, "You got it on tape? Arnold, 654!"

Using the video as evidence, the teen's mother filed a complaint with the Hurst Police Department that led to an internal affairs investigation. The mother said she hoped the officer would either turn in his badge or be fired.

Dashcam video released several days later showed the teen, prior to Arnold arriving at the scene, arguing with Officer Miguel Jimenez and resisting arrest -- a offense for which he was charged.

On Thursday, Hurst police said Arnold was "indefinitely suspended for violations of Hurst Police Department General Orders and Civil Service rules relating to his actions on Nov. 20, 2012" and "an internal affairs investigation was conducted for violations ... to include the unnecessary use of force, being disrespectful to a citizen, and the use of indecent, profane, or harsh language in the performance of official duties."

Despite Pope's claim of excessive force, the internal affairs investigation determined the amount of force used by Arnold was reasonable since he believed Jimenez was struggling to subdue the teen.

The investigation did find, however, that Arnold was disrespectful to a citizen and "used indecent, profane, and harsh language in the performance of his official duties, and conducted himself in a manner which brought discredit to himself and the Hurst Police Department."

"You can't help but be embarrassed -- not only for the officers that work in our department, but for anybody in the law enforcement profession," Hurst Assistant Chief Steve Niekamp said in November. "You just expect when an officer shows up, they're going to be in charge. You don't want the foul language, anything that looks like it might be overreaction. You just want to be professional, calm and in control of the scene."

Prior to the department's latest ruling, Arnold had been placed on administrative leave.

Arnold had been with the department for four years and, according to a performance assessment and disciplinary file released by Hurst police after the incident, he met or exceeded police standards in nearly every assessment. The document also noted in May, 2010, that "Officer Arnold's enthusiasm may make him overzealous at times, which can cloud his judgment when it comes to policy, procedure and tactics. Sometimes he needs to step back and see the big picture and risks involved."

Arnold has 10 days to appeal the termination.

NBC 5's Scott Gordon contributed to this report.

A Chicago police officer who was shot in the chest while pursuing a curfew violator on the city's South Side is in critical condition after surgery, but his prognosis is good, a police spokeswoman said.

The 47-year-old officer and others had approached four curfew violators late Monday night to conduct a field interview, said officer Laura Kubiak.

"One of the subjects fled the scene into an alley," she told msnbc.com, reading from a police statement. "An officer pursued the offender into a front yard where the offender fired shots striking the officer in the upper body. The offender fled the scene."

The eight-year veteran of the force is being treated at Advocate Christ Medical Center, where doctors were able to stem the bleeding, Kubiak said.

The officer, who had been wearing a bullet-proof vest, lost two-thirds of the blood in his body. Surgeons did not remove the bullet,
Fraternal Order of Police spokesman Pat Camden told NBCChicago.com.

The bullet is lodged next to the officer's spine, Supt. Garry McCarthy told reporters: "It's not bad news, but it's not the type of news we want to hear."

Related: Chicago bloodbath: 6-year-old among 10 killed

A person of interest --  20 years old, believed to have gang ties -- was being questioned, the Chicago Tribune reported.

The officer's wife, two children, mother and pastor were at the hospital, McCarthy said.

"This guy's a great cop," he said. "There's a very somber mood. Everyone's very serious and focused on praying for his recovery right now."

Msnbc.com's Miranda Leitsinger contributed to this report.

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Virginia State Police via AP

Police identified the Virginia Tech gunman on Friday as Ross Truett Ashley, 22, a part-time college student from nearby Radford University.

BLACKSBURG, Va. -- The man who authorities say killed a Virginia Tech police officer was described as a typical college student in many ways, making it difficult to understand why he would commit an armed robbery and then, apparently at random, target the patrolman before killing himself.

The gunman was identified Friday as Ross Truett Ashley, a 22-year-old part-time business student at Radford University, about 10 miles from the Virginia Tech campus in Blacksburg. He first drew authorities'attention Wednesday when, they say, he walked into his landlord's office with a handgun and demanded the keys to a Mercedes-Benz SUV.

As investigators worked to unravel a motive, thousands of people gathered for a candlelight vigil Friday night on a campus all too familiar with tragedy.

Those who knew Ashley said he could be standoffish. He liked to run down the hallways and recently shaved his head, a neighbor said.

Virginia State Police said he walked up to officer Deriek W. Crouseafter noon on Thursday and shot him to death as the patrolman sat in his unmarked cruiser during a traffic stop. Ashley was not involved in the stop and did not know the driver, who is cooperating with police, they said.

Authorities said Ashley then took off for the campus greenhouses, ditching his pullover, wool cap and backpack as police quickly sent out a campus-wide alert that a gunman was on the loose. Officials said the alert system put in place after the nation's worst mass slaying in recent memory worked well, but it nevertheless rattled a community still coping with the day a student gunman killed 32 people and then himself.

A deputy sheriff on patrol noticed a man acting suspiciously in a parking lot about a half-mile from the shooting. The deputy drove up and down the rows of the sprawling Cage parking lot and lost sight of the man for a moment, then found Ashley shot to death on the pavement, a handgun nearby. No one saw him take his life and he wasn't carrying any ID.

State police spokeswoman Corinne Geller said Ashley appears to have acted alone and didn't know the slain officer: "At this time we have no connection between the two of them, that they knew one another or had encountered one another prior to the shooting," she said.

'Nothing unusual'
Ashley lived in an apartment on the top floor of a worn, gray three-story brick building in the small city of Radford, a college town. He lived above a yogurt shop, consignment store, barber shop and a tattoo parlor.

On Friday night, students popped in and out of the building visiting friends. Mandy Adams, a Radford grad student, said Ashley had recently shaved his head. Other than running down the hallways, he was quiet, she said.

"He would just run down the hallway — never walk, always run," said Adams, who was out on a rear fire escape with a glass of white wine and a cigarette to calm her nerves. "It's going to be really creepy when they come to take his stuff out of here."

Neighbor Nan Forbes, a Radford senior, said Ashley was rarely seen or heard from. She said she knew he was in trouble when she saw two police officers guarding the door to his apartment

"It does freak us out because we live in this building, but there was not one peep of trouble, nothing unusual," she said.

Ashley made the dean's list in 2008 at the University of Virginia-Wise, which is located in southwest Virginia. He took classes at Radford, a former state teachers college in the Blue Ridge Mountains that now has more than 9,000 students.

AP

Deriek Crouse, a 39-year-old Army veteran, was a married father of five. He previously worked at a jail and a sheriff's department. (AP Photo/Virginia Tech)

Officials at Radford or UVA-Wise were not immediately able to talk in detail about Ashley.

At the Virginia Tech campus, thousands of people silently filled the Drillfield for a candlelight vigil Friday night to remember Crouse, a firearms and defense instructor with a specialty in crisis intervention. He had been on the campus force for four years, joining it about six months after the April 16, 2007 massacre.

Crouse was a member of the Army Reserves who served a year in Iraq beginning in March 2004, according to the U.S. Army Human Resources Command. He was assigned to active duty service at Fort Hood, Texas from October 1993 until July 1996, where he was listed as an M1 armor crewman, or tank operator. From July 1996 to May 2001, Crousewas listed as a motor transport operator with the 316th Sustainment Command in Galax, Va. Crouse's last rank was staff sergeant.

For about nine months in 2007, Crouse worked as an officer with the Montgomery County Sheriff's Office at the county's jail before leaving for the Virginia Tech police, said Capt. Brian Wright, a spokesman with the department.

Those who worked with Crouse remembered him as a "great employee" and a "hard worker," said Wright, who had worked security with Crouse at Virginia Tech football games.

"He was just very personable, easy to talk to," Wright said. "Everybody liked him."

The Friday night vigil included a moment of silence and closed with two trumpeters stationed across the field from each other playing "Echo Taps" as students raised their candles.

"Let's go!" one student then shouted.

"Hokies!" everyone else responded.

'Go home and hug my mom'
Kathleen O'Dwyer, a fifth-year engineering major at Tech, said it was important to come for Crouse's family. Crouse was married and had five children and stepchildren.

"Also it's for the community, to see the violence that happens isn't what we're about," said O'Dwyer, who will be graduating next week.

Her plans when she leaves school?

"First, go home and hug my mom," O'Dwyer said.

Nobody answered the door Friday evening at Ashley's parents' home in Spotsylvania County, along the Interstate 95 corridor between Richmond and Washington. The house was dark and no vehicles were in the driveway. The two-story, log cabin-style home in a semi-rural area sits about 200 yards off the road up a narrow gravel drive.

Billie Jo Phillippe, who lives three houses down, said she didn't really associate with the family.

"They stay off to themselves a lot," she said. "He was a clean-cut young guy but standoffish."

Authorities declined to answer some questions about Ashley, including whether he had any mental health issues or was licensed to carry a handgun.

But Gov. Bob McDonnell commented briefly on the shooting while helping load presents into a van for the Marine Corps Reserves' Toys for Tots program.

"Some crimes, there's a relationship between a perpetrator and a victim, and some there aren't," said McDonnell, a former prosecutor and attorney general. "There are random acts of violence, they involve either mental health issues, or robbery, or other motivations....Unfortunately in our society random acts of violence do occur, we unfortunately see it every day somewhere in this country."

He said there's an "extra degree of scrutiny" of incidents at Virginia Tech because of the 2007 mass shooting.

"It's just unfortunate and almost inexplicable that you could have a series of these events happen in a short four-year period," the governor said. 

Flowers lie on the ground as a memorial to Virginia Tech police Officer Deriek Crouse who was gunned down Thursday during a traffic stop on the campus of Virginia Tech in Blacksburg, Va., Friday. (AP Photo/Steve Helber)

Lewis reported from Radford. Associated Press writers Michael Felberbaum, Larry O'Dell, Steve Szkotak and Dena Potter in Richmond, Va., Brock Vergakis in Norfolk and Eric Tucker in Washington contributed to this report.