SAN FRANCISCO -- A 22-year-old man was found guilty Wednesday of raping and sexually assaulting a 15-year-old girl in a Hunters Point apartment in October, San Francisco District Attorney Kamala Harris announced Thursday.

Following a four-week trial, Arvin Mackey was convicted of rape and sexual penetration with a foreign object, the district attorney's office reported.

The victim had been on her way to school when she met Mackey on Oct. 3, 2007. According to the district attorney's office, Mackey took the victim to an apartment in Hunters Point and sexually assaulted her. Following the assault, he drove around the area for a number of hours and then dropped her off in the Mission District, the district attorney's office reported.

The victim called her parents to notify them of the attack and police took her to San Francisco General Hospital for a medical examination. Physical and DNA evidence from the examination corroborated with the victim's account of the incident and police arrested Mackey on Oct. 7, according to the district attorney's office.

"This young victim was courageous in coming forward to report this gruesome attack and showed true courage in testifying against the man that violated her," Harris said in a prepared statement. "I am grateful that the jury held the defendant to answer for this brutal crime because the victimization of our children must be met with swift and severe consequences."

Following four days of deliberation, the jury found Mackey guilty of rape and sexual assault charges, but did not reach a guilty verdict on a charge of forced oral copulation, according to the district attorney's office. He was acquitted of an aggravated kidnapping charge.

The maximum penalty for rape and sexual penetration with a foreign object is 16 years in state prison.

Mackey is scheduled to be sentenced on July 31.