Authorities say DNA evidence has linked the 33-year-old man to five sexual assaults that occurred in Ocean Beach, Mission Beach and College Area between June 2000 and February 2001. Richardson was in the Navy and based at Marine Corps Air Station Miramar around that time.
He was arrested last month in Arlington Heights, Ill.
Richardson faces 23 felony charges. He may also be linked to an assault in Arlington Heights.
The most recent of these rapes was six years ago in Arlington Heights. The San Diego crimes happened about nine years ago. But they got quite a bit of attention at that time. On at least five occasions, the rapist went into young women's homes through unlocked doors or windows late at night or early in the morning.
Police say Richardson studied his victim's routine before each attack.
"They're primarily forcible sex crimes, including forcible rape, forcible sexual penetration…He's also been charged with residential burglary," said Elizabeth McClutchey, San Diego Deputy District Attorney.
It was DNA evidence from Arlington Heights police that broke the case. Police in the northwest suburb found DNA from a 2003 rape there matched evidence found in the San Diego crimes. Police apparently also have a fingerprint match.
After his military discharge, he moved to the Chicago area. Arlington Heights police arrested him outside his home in mid-August, and he was extradited to San Diego. People there still vividly remember his alleged crimes. Many of the victims were college students.
"I just remember not really wanting to walk around the streets and stuff by myself knowing that something like that had happened in my home town," said Leeann Depace, San Diego resident.
Alex Acevedo lives next door to where one young woman was attacked. The rapist went in through her bedroom window.
"It was sad. It was painful to know that somebody next door that you know was raped at knife point in her own home in a neighborhood where at the time you thought it was safe," said Acevedo.
While it was DNA that linked the Arlington Heights rape to the San Diego rapes, according to his arrest warrant, it was a single fingerprint that finally led police to Richardson in July.
Arlington Heights police have not said whether they will pursue charges against Richardson after his trial in San Diego.
Richardson was being held on $1 million bond.
The Associated Press contributed to this report.