The accused, identified as Raghvendra Reddy, is married with two kids and was known to the victim's family, they said.
According to police, Reddy entered the victim's house at around 6.30 pm and after reportedly arguing with her mother over some dispute "attacked the girl with a knife and slit her throat which resulted in her death on the spot".
"He later tried to kill himself by slashing his throat and was rushed to a private hospital," they said, adding the exact motive behind behind the crime was not known yet.
The teenager was a first-year graduation student, police said.
Ibrahimpatnam Police have registered a case of murder against Reddy for murder and other sections of IPC.
