View Photo Gallery: Aaron Thomas is accused of a series of rapes and attacks on more than a dozen women since the late 1990s.

The case against Aaron H. Thomas, the alleged East Coast Rapist, will move forward after a Prince William County judge on Thursday certified multiple charges to a grand jury.

Thomas, 40, who grew up in Prince George’s County and most recently lived in New Haven, Conn., has been connected to more than a dozen rapes and attempted rapes in Virginia, Maryland, and Connecticut dating back to the 1990s. Police long knew the attacks on apparently random women were linked to one person based on DNA evidence left at numerous crime scenes. In court on Thursday, Prince William prosecutors said Thomas is that man.

The hearing Thursday largely was a formality in what will be a case that carries the potential for several life sentences and will rely heavily on forensic evidence and Thomas’s own admissions to police officers after his arrest last year. It was the Halloween 2009 rapes of two teenaged trick-or-treaters in Woodbridge that re-energized the decades-long investigation, drew significant media attention and led detectives to re-examine crime scenes in several states. That new focus – and an anonymous tip to police – combined to put the spotlight on Thomas.

Perhaps the most brazen of his alleged attacks, the Halloween rapes were the first in the series to involve three victims, and police believe they were the last linked to Thomas. He allegedly accosted three friends who were on their way home after trick-or-treating and forced them down a steep embankment to a wet, tree-filled ravine. While he allegedly raped two of the girls in succession, threatening them at gunpoint, the third teenager told the Post in 2010 that she summoned help with furtive text messages and phone calls to 911.

Police, responding extremely quickly, barely missed Thomas as he fled out of the area in darkness. Detectives theorized that whoever carried out the attack most likely was familiar with the area; Thomas once owned a home in a nearby neighborhood.

Since his arrest, authorities have been able to place Thomas in close proximity to the locations of attacks in Prince George’s County, Loudoun County, Fairfax County, and New Haven, based largely on places Thomas lived or where he had relatives.

Police believe Thomas spent time watching some of his alleged victims prior to attacks, as some of the rapes involved a suspect entering through unlocked doors or windows when a victim was alone in a home, and victims told the Post that their attacker said things to indicate he was aware of their schedules or family situations. Other rapes, in which victims were approached outside, appeared to have been planned because victims were taken to what appeared to be pre-selected secluded areas, many of which resembled other attack locations.

Thomas was first charged with rape in Connecticut but was transferred to Virginia last year under an agreement between the two states that will allow Prince William County Commonwealth’s Attorney Paul B. Ebert to try him. Ebert also was handpicked to prosecute Washington-area sniper John Allen Muhammad.

It is unclear if Thomas also will face trial in other Washington area counties, where he allegedly raped people after approaching on a bicycle or on foot and allegedly used a variety of weapons to threaten and subdue victims.

More from The Washington Post:

Get ready for an early cherry blossoms’ peak

Virginia Senate kills ‘Tebow’ bill

Police: Officer who ticketed official didn’t have time to gauge her pace