The rapper, one of the world's biggest hip-hop acts, faces one year in jail for attempted gun possession after DNA evidence was found to be admissible in court

Lil Wayne faces one year in jail after pleading guilty to gun possession yesterday. The New Orleans rapper – one of the world's biggest hip-hop acts – reversed his plea after "problematic" DNA evidence was found to be admissible in court.

The hearing yesterday (22 October) didn't take long. Beginning at 10am and lasting just 20 minutes, the session saw Lil Wayne formally accept the district attorney's plea deal, confirm to the judge he understood the terms, and concede that the type of gun he had illegally possessed was "a .40-calibre semi-automatic". Leaving the New York courtroom in jeans, grey coat and a white T-shirt, Wayne – born Dwayne Carter – asked reporters, "What's up?"

What's up were the charges dating from an incident in July 2007, the night of Lil Wayne's first headlining concert in New York. NYPD pulled over the rapper's tour bus at about 11:30pm, at which point a Louis Vuitton bag was allegedly tossed from the bus. It contained a handgun.

Lil Wayne was arrested that night for criminal possession of a weapon while another man was charged with criminal possession of marijuana. Until this week Lil Wayne had pleaded not guilty to the charges, but on Tuesday his story changed, after a judge ruled that "miniscule" amounts of DNA found on the gun would be admissible in court. Lil Wayne's lawyer, Stacey Richman, described this DNA evidence as "problematic". By accepting the plea deal, the rapper has avoided a January 2010 trial where he would have faced up to three and a half years in jail.

Instead, Lil Wayne has pleaded guilty to "attempted" gun possession in the second degree and will be sentenced to one year in prison, the district attorney's office said. Assuming good behaviour, the rapper will only serve eight to 10 months. Formal sentencing will not take place until February, however, and for the moment Lil Wayne is free on bail. He is thought to have spent yesterday celebrating the first birthday of Dwayne Carter III, his eldest son.

According to lead prosecutor, Joan Illuzzi-Orbon, gun possession can take two forms: "actual possession" or "dominion and control". Whereas "actual possession" means someone owns and carries the gun, "dominion and control" means that the weapon is available for immediate use, such as on a tour bus. "[In this case] we said it was dominion and control," Illuzzi-Orbon told MTV News. That is, Lil Wayne's "attempted gun possession" plea is a concession that the gun might not have been in the rapper's hand, but that it was on the bus and thus within his "control".

"After ongoing negotiations, [Lil Wayne] opted to take the deal to take responsibility for the situation and I think it speaks of him that he's an individual with a strong constitution who took that responsibility," Richman told reporters. She said that the .40-calibre gun had been purchased by the rapper's manager, Cortez Bryant, who had a permit to carry it in Mississippi.

Lil Wayne is the second major rapper this year to be found guilty on weapons charges. His past collaborator TI is currently serving a 366-day sentence for attempting to buy unlicensed machine guns and silencers in 2007.

Lil Wayne has much to do as he awaits his February court date. The world is still waiting for his much-delayed "rock" album, Rebirth, as well as Tha Carter IV, his next hip-hop LP. Both are expected before Christmas. Then again, Lil Wayne has other legal issues to worry about: he faces trial in Arizona following a separate incident last year, when police found marijuana, cocaine, ecstasy and a handgun aboard the rapper's tour bus.