LOS ANGELES (REUTERS) - A California man who prosecutors say secretly took pictures up the skirts of hundreds of women and is already serving 15 years in prison was sentenced on Friday to five more years behind bars.

Mylyn Coriche Johnson, 31, was sentenced to the extra time behind bars after he was convicted at retrial on July 27 of five additional misdemeanor counts of taking so-called up-skirt pictures, Los Angeles County Deputy District Attorney Theodore Swanson said.

Swanson said that between August 2012 and March 2013 the defendant, who is also known as Lamar Quinn, used his phone to shoot photos up the skirts and dresses of women shopping at several stores in the Southern California city of Lancaster, some 65km north-east of Los Angeles.

In February 2013, Johnson also posed as a security guard at a Kmart in Lancaster, patting down a woman as he claimed to look for stolen merchandise, according to Swanson.

He was arrested at a Target store in March 2013 after a woman told security that he was following her and her sister through the aisles.

Johnson was convicted in September 2013 of a total of 14 counts: one felony count each of sexual battery by fraud and false imprisonment by violence and 12 misdemeanor counts of video or photography of a person in undergarments.

After an appeals court overturned five of the misdemeanor counts against Johnson, he was retried and again convicted on those counts.

His total sentence now stands at 20 years and six months in state prison, according to prosecutors.