(CNN) -- The man accused of being the so-called "East Coast Rapist" casually spoke with authorities about his arrest, asking, "What took you so long to get me?" a prosecutor said Monday.
Aaron Thomas, 39, made his first appearance in court Monday, three days after authorities arrested him as he walked near his home in New Haven, Connecticut. A judge ordered him held on $1.5 million bond in a 2007 sex assault case in New Haven.
He is linked to sexual assaults on 17 women in Maryland, Virginia, Connecticut and Rhode Island between 1997 and 2009, according to police.
Police placed Thomas under surveillance last week after receiving a detailed tip generated by a billboard campaign and website that tallied 169,000 page views, according to Fairfax County, Virginia, police Chief David Rohrer.
Authorities tailing Thomas collected a cigarette butt he discarded outside a courthouse where he was appearing on a larceny charge, Supervisory Assistant State's Attorney David Strollo said.
DNA from the cigarette linked him to the assaults, according to police.
Thomas appeared in court Monday wearing a hat and sunglasses, guarded by five bailiffs. He kept his head down during the seven-minute hearing, during which Strollo detailed allegations against him, including accusations that he abducted three girls -- raping two of them at gunpoint -- in a 2009 attack in Prince William County, Virginia.
He is accused in the January 2007 rape of a New Haven woman in front of her 1-year-old, threatening to kill the child if the woman did not comply.
Thomas told authorities after his arrest that he has a " 'Dr. Jekyll and Mr. Hyde' personality when it came to women," Strollo told the court.
Police were already looking at Thomas in the case: His name was on a short list of suspects generated from analysis of millions of records of interactions with police and other agencies contained in a Virginia police database, according to Detective John Kelly of the Fairfax County police.
The tip that broke the case came to authorities in Prince George County, Virginia, where Thomas is facing charges in four sexual assault cases. The tip, according to Thomas' arrest warrant, said Thomas had "taken credit for the first attack" in Forestville, Maryland.
"We always suspected a tip would lead us to a successful conclusion of this case." Rohrer said.
Prince William County Commonwealth Attorney Paul B. Ebert called news of the arrest "music to my ears."
"This case concerned me almost as much as the D.C. sniper case did," said Ebert, referring to the shooting attacks that terrified residents of Washington, Maryland and Virginia in 2002.
On Saturday, Thomas tried to hang himself in his cell, according to police. He was briefly taken to Yale-New Haven Hospital for evaluation before being returned to his cell and placed on suicide watch.
He was not injured in the suicide try, according to police.
CNN's Raelyn Johnson contributed to this report.