A student faces jail after he was caught carrying a gun on college premises, police said.
Adamo Kizey, 18, was found with a semi-automatic pistol and magazine containing six rounds of ammunition when he was searched at Kingston College in south London.
Appearing at Kingston Crown Court on Friday, he pleaded guilty to possession of a firearm with intent to endanger life, possession of ammunition with intent to endanger life, possession of a silencer and possession of cannabis.
Detective Chief Inspector Peter Beyer, from the Metropolitan Police, said: "This student was carrying a firearm on college property which posed a significant safety risk to students and teaching staff, as well as the wider community."
Officers from the Met's Central Task Force apprehended Kizey at the college in February this year.
The officers were acting on intelligence that the teenager had been dealing drugs in the area.
Kizey was called to a room at the college where officers were waiting.
He was told that he had been called in to be detained and searched. When asked if he had anything on him, he replied "No".
Officers then searched him and discovered a black semi-automatic pistol inside his jacket, and a magazine containing six rounds of ammunition in his outer pocket.
He was taken to his home at Cambridge Gardens, Kingston-upon-Thames, where they searched his bedroom and discovered 20 wraps of cannabis in a jacket pocket, a silencer for the pistol, kept in a white sock at the bottom of his wardrobe, and a set of digital weighing scales.