A man who pleaded guilty in several Phoenix sexual assault cases has been sentenced to 50 1/2 years in prison.
Maricopa County prosecutors said 19-year-old DeJuan Donaldson also was sentenced Friday to lifetime probation.
He pleaded guilty in January to two counts of sexual conduct with a minor, two counts of attempted sexual assault with a minor, sexual assault and attempted sexual assault.
But in February, he fired his attorney and withdrew his plea.
"I wish to withdraw from this plea because I was forced to sign it. I'm the one doing the time if you choose to deny this motion," Donaldson said in court Friday.
He later pleaded guilty again.
Donaldson was arrested in May 2011, one month after a reported attack on a South Mountain High School student.
The then-17-year-old girl told police she was walking to school when she was accosted by a man, taken at knifepoint into an abandoned house and sexually assaulted.
Police took Donaldson's DNA and believe he was linked to three other sexual assaults in November 2010 and January 2011.
Under Arizona's mandatory sentencing laws for offenses classified as dangerous crimes against children, Donaldson will not be eligible for early release.
Copyright 2013 Associated Press. All rights reserved. CBS 5 (KPHO Broadcasting Corporation) contributed to this report.