Three Florida-based police officers have been fired and a fourth has been forced to resign after exchanging racist texts and creating an N-word-laced video featuring President Barack Obama. James Wells, 30, Jason Holding, 31, and Christopher Sousa, 25, who patrolled a predominantly black neighborhood in Fort Lauderdale, were sacked on Friday for 'department misconduct'. Meanwhile, Alex Alvarez, 22, who apparently created the video, resigned from the city's force in late January, before the five-month  investigation into he and his colleagues' exchanges was complete. The job losses come at a critical moment in the United States as police officers across the nation continue to come under fire for the alleged use of excessive force against African Americans. WARNING: OFFENSIVE MATERIAL . Scroll down for video . Firings: Three Florida-based police officers have been fired and a fourth has been forced to resign after exchanging racist texts and creating an N-word-laced video featuring President Barack Obama. Above, Fort Lauderdale Police Chief Frank Adderley (far right) speaks about the firings at a press conference on Friday . 'Offensive': The iMovie video, apparently created by Alex Alvarez,  displayed 'racially insensitive' images of  a person in a white Ku Klux Klan hood (left) and a caricature of President  Obama with gold-capped teeth (right) 'Racist': The video,  created in the style of a film trailer, also showed images of minority attacks and racist on-screen captions. Above, the words, 'But one n***** would change everything', preceeded the photo of Obama . All of the four officers involved in the case committed misconduct involving racist texts 'exchanged among themselves and former police officers', Fort Lauderdale Police Chief Frank Adderley said . Chief Adderley, who is African-American, added that the officers did not engage in criminal behavior, 'but their conduct was inexcusable and there is zero tolerance for this kind of behavior' in the force. In their cellphone messages, the officers sent each other 'racial, sexist and ethically inappropriate' images and other content, including offensive comments against both Hispanics and homosexuals. They also 'criticized their coworkers' grammar, appearance, work ethic and referred to an entire shift as lazy (expletives)'. And they  even talked about killing and injuring black people, CBS reported. In one text, Sousa reportedly wrote: 'Holdings we are coming and drinking all your beer and killing n******.' In another, Holding said: 'Id have that noose ready (sic)', according to the Sun-Sentinel. Meanwhile, in Alvarez's 'movie trailer-style' iMovie video, the officer displayed 'racially insensitive' behavior by including images of attacks on minorities and a person in a white Ku Klux Klan hood. Texts: All of the four officers committed misconduct involving racist texts 'exchanged among themselves and former police officers', Chf Adderley said. Above, in this text, Christopher Sousa refers to killing n******' 'Misconduct': In a response to Jason Holding, his colleague James Wells calls someone a 'retarded brown' 'Ethically inappropriate': In another text message, Holding writes: 'Id have that noose ready' - in reference to black men. Holding,  Wells and Sousa, all of Fort Lauderdale. were sacked Friday for 'department misconduct' The disturbing footage, which apparently used the N-word repeatedly, also featured pictures of a wanted poster for 'an escaped slave' and a caricature of President  Obama with gold-capped teeth. And it included photos of black men being bitten by a dog and looking down the barrel of a gun. An internal affairs investigation was launched into the four officers' conduct last October after Alvarez’s former fiancée emailed screenshots of their racist text exchanges to Chief Adderley. Following the allegations, Wells, Holding, Sousa and Alvarez were dismissed from their normal duties. In January, Alvarez resigned. The other three  were  sacked for misconduct this week. Disturbing: Officer Alex Alvarez, 22, who apparently created the video (pictured: a still), resigned from the city's force in late January - before the  investigation into he and his colleagues' exchanges was complete . Shocking: The video for the ficitious 'The Hoods' film, which apparently used the N-word repeatedly, featured pictures of a wanted poster for 'an escaped slave' and black men looking down the barrel of a gun (pictured) Brutal: It also included photos of black men being bitten by a dog (pictured), a police investigation determined . The firings were based on 'sustained department misconduct and ... conduct unbecoming of a police officer', including the 'Uncle Al Films' video for  'The Hoods' movie, according to WSVN.com. Chief Adderley told NBC Miami the officers had told him they had been just joking around. 'Based on the investigation, they felt, in their words, that it was a joke,' he said at a news conference Friday . However, Alvarez's fiancée, who has not been identified, reportedly told investigators that her officer ex-lover had thought that 'black people should be slaves' and  was obsessed with the 'KKK'. Fort Lauderdale Mayor Jack Seiler said he was 'very disappointed, disgusted and shocked' by the inquiry's findings, describing the officers as 'a few bad apples' in a 'diverse' police department. 'Disappointed': Fort Lauderdale Mayor Jack Seiler (second right, alongside Chf Adderly, far right) said he was 'very disappointed, disgusted and shocked' by the inquiry's findings, describing the officers as 'bad apples' 'Just a joke': Chf Adderley (pictured) revealed the four officers had told him they had been just joking around. 'Based on the investigation, they felt, in their words, that it was a joke,' he said at a news conference Friday . Listening: Police officers listen as Cf Adderley talks to the media on the results of the internal affairs inquiry . He added city and department leadership had agreed that the multiple sackings were appropriate. Meanwhile, City Manager Lee Feldman said: 'It's extremely unfortunate that these acts of racism and hatred took place'. He also expressed his thanks toward Alvarez's fiancée for coming forward. The police department in south-east Florida, which has around 500 agents, has now created a human diversity class that all officers must attend on an annual basis in the wake of the incident. The Fraternal Order of Police Lodge #31 represents the officers. FOP President Jack Lokeinsky said everyone is entitled to due process, and the officers have the right to a fair review of the facts. Headquarters: The police department (pictured) in south-east Florida, which has around 500 agents, has now created a human diversity class that all officers must attend on an annual basis in the wake of the incident .
James Wells, Jason Holding and Christopher Sousa were fired on Friday . Colleague Alex Alvarez, 22, resigned in late January during investigation . Officers exchanged 'inexcusable' racist text messages, police chief said . Messages referred to 'killing n******'; one said, 'I'd have that noose ready'
Alvarez also created video featuring Obama sporting gold-capped teeth . Other clips included pictures of attacks on minorities and use of N-word . Fort Lauderdale Mayor Jack Seiler said at a press conference that he was 'very disappointed, disgusted and shocked' by investigation's findings .