U.S. football star Michael Vick publicly apologized on Monday (August 27) after pleading guilty in a dogfighting case that will almost certainly land him in jail and prompted his suspension from the sport. "I want to apologize for all the things I've done and all the things I've allowed to happen," Vick, 27, told reporters after entering his plea. "Dogfighting is a terrible thing and I do reject it." "I take full responsibility for my actions," he said. "What I did was very immature, I need to grow up." Earlier in the morning, the Atlanta Falcons star was greeted by chants and boos as he entered a the U.S. courthouse to formally plead guilty in a dogfighting case almost certain to wreck his football career. Vick, dressed in a blue suit and yellow tie, did not acknowledge the loud screams, chants and boos from a crowd gathered across the street from the courthouse as he arrived for his 1030 EDT (1430 GMT) hearing. Vick appeared before U.S. District Judge Henry Hudson to formally plead guilty. In a plea agreement filed with the court on Friday, Vick admitted he took part in an illegal, interstate dogfighting enterprise known as Bad Newz Kennels from 2001 through April 2007. In the court documents, Vick said he knew dogs that did not perform well were killed and admitted to being involved in the killing of at least eight dogs earlier this year. He said he bought property in Virginia to serve as the main staging area for housing and training pit bulls that took part in the dogfighting venture. Vick, who has been suspended indefinitely by the National Football League, faces a maximum of five years in prison, a fine of $250,000 and three years of supervised release. If he cooperates, he will likely be given a shorter prison sentence that many expect to be between 12 and 18 months in prison. The judge is not bound to accept the deal and will be the one to decide the sentence, likely in November or December. After the plea agreement was made public, Nike Inc terminated its contract with Vick, calling the dogfighting enterprise "abhorrent." Nike had previously suspended the release of a new Michael Vick shoe that had been set to hit stores this month and Reebok stopped selling his jerseys. Demonstrators had mixed views of Vick, who signed a 10-year, $130 million contract with the Falcons in 2004. Vick's decision to plead guilty came after his three co-defendants made their own plea deals with the understanding they would testify against the quarterback. Dogfighting, in which two dogs bred to fight are placed in a pit to attack each other for spectators' entertainment and gambling, is illegal in the United States. Prosecutors charged that dogs sometimes fought to the death and that some underperforming animals had been shot, drowned, hanged, electrocuted or killed by being slammed to the ground. Vick, one of the most dynamic players in the NFL, said he knew that mediocre dogs were killed from 2002 to 2007 and was involved in at least the killing of eight of them. "All of those dogs were killed by various methods, including hanging and drowning," the documents said. "These dogs all died as a result of the collective efforts" of him and his partners. The top pick in the 2001 NFL draft out of Virginia Tech, Vick has made more than $61 million in his six NFL seasons. A rare talent who threw for 20 touchdowns and ran for more than 1,000 yards last season for the Falcons, he has been heavily criticized in the media and by animal rights groups.