Phelps, 29, failed two roadside sobriety tests and was asked to perform a third involving balancing on one leg, according to the documents, but told the officer, "That's not happening."
The swimmer, who returned to competition last year after retiring in 2012 as the most decorated Olympian of all time, is scheduled for trial on Nov. 19 in Baltimore City District Court. He is charged with driving under the influence, excessive speed and crossing double lane lines.
Phelps, stopped shortly before 1:40 a.m. Tuesday after leaving the just over 1-month-old Horseshoe, told the Maryland Transportation Authority officer that he had had three or four drinks there, the documents said.
His drunken driving arrest raised concerns at the city's liquor board, which is calling on casino officials to provide more information about whether servers should have continued serving Phelps.
"We sent a message to their attorneys asking what's going on," said Michelle Bailey-Hedgepeth, director of the liquor board. "We have a rule about over-service. Any establishment has to follow our rules."
The liquor board prohibits any bar in the city from selling alcohol to someone who is "under the influence," "disorderly" or "known to be a habitual drunkard."
The casino is unique in the city in possessing the only 24-hour a day liquor license. Other establishments must stop serving alcohol to patrons at 2 a.m. except on the night of New Year's Eve.
Noah Hirsch, Horseshoe's vice president of marketing, said it would be inappropriate to comment on an ongoing investigation.
A spokeswoman for the Maryland Lottery and Gaming Control Agency said that the sale of alcohol at casinos is regulated by the local liquor board. Casinos are not required to report DUI arrests of their patrons to the regulatory board, said Erica L. Palmisano, assistant communications director of the gaming agency.
"This is really a law enforcement and alcohol control board issue," she said.
State law prohibits vendors with a liquor license from selling or providing alcohol to anyone under the age or 21 or someone "visibly under the influence of any alcoholic beverage."
But Andrew Bederman, a Silver Spring-based lawyer, said his firm's research found that every prosecution under that law dealt with underage patrons. Additionally, he said, Maryland is one of eight states in which bars can't be held civilly liable for serving intoxicated patrons.
"In Maryland there appears to be a criminal law that's not enforced, and there's no civil liability whatsoever," Bederman said.
No lawyer was listed for Phelps in the court documents, and his representatives have not responded to requests for comment. Phelps apologized on Twitter on Tuesday, saying he took full responsibility for his actions and was "deeply sorry to everyone I have let down."
This was Phelps' second arrest for drunken driving. In 2004, when he was 19, Phelps pleaded guilty to driving while impaired in Wicomico County. In 2009, British tabloids published pictures of him smoking a marijuana pipe at a college party.
The documents released Wednesday provided further details of Phelps' arrest:
An MdTA officer saw a white Range Rover speeding southbound on I-395, and a stationary radar unit clocked it as going 84 mph hour in a posted 45 mph zone. The officer followed the Range Rover onto the ramp to northbound I-95, where the vehicle drifted out of its lane and continued to speed as it entered the Fort McHenry Tunnel.
The vehicle changed lanes inside the tunnel, at one point passing in front of a tractor-trailer.
The officer stopped the vehicle just past the tunnel's toll plaza and "smelled a strong odor of an alcoholic beverage emitting" from it. The officer described Phelps' eyes as "red" and "bloodshot," and his speech as "mush mouth."
Phelps told the officer he had been at the Horseshoe and had had three or four drinks, the last about two hours earlier. The officer then explained three field sobriety tests, and Phelps said he understood.
The first, an eye test, indicated "the presence of alcohol," the officer wrote. A walk-and-turn test was then given, and Phelps said he had "a bulging disk in his neck and back." The officer said Phelps had "trouble maintaining his balance." After declining the third test of balancing on one leg, Phelps was arrested.
He then said he wanted to take the test but Phelps "appeared disoriented, argumentative, and did not attempt the test," the officer wrote.
Phelps was taken to the MdTA police station, where he was given a breathalyzer test that measured 0.14 grams of alcohol per 210 liters of breath.
The Tuesday arrest drew expressions of disappointment from the swimming community, which views him as the face of the sport and was thrilled he returned to competition.
The executive director of the sport's governing body, USA Swimming, Chuck Wielgus, told USA Today columnist Christine Brennan on Wednesday night that the organization is considering possible action. (He was suspended from competition for three months in 2009 after the pictures surfaced of him smoking a marijuana pipe.)
"Michael's contributions to the sport are countless," Wielgus said in an email, according to Brennan. "However, we have to look at this through an objective lens as his actions were irresponsible, reckless and not what we would expect from our National Team athletes. We are considering all possible options and our due diligence takes time."
It also threw into question whether Phelps would continue to draw the kind of corporate sponsorships that have made him tens of millions of dollars over the course of his unparalleled Olympic career.
Several sponsors called about Phelps arrest did not respond to requests for comment.
A friend of Phelps' — Steve Dannenmann, an accountant from Severn who won second place and $4.25 million in the 2005 World Series of Poker — said the swimmer enjoys playing poker and going to casinos as a break from his rigorous training.
"Everyone needs an out, an escape," Dannenmann said. "It's just about having fun."
Dannenmann met Phelps when the swimmer approached him about eight or nine years ago at an Atlantic City casino and told him he had seen him play on TV and admired him. They eventually became friends, playing poker and golf together and occasionally visiting casinos.
"I can see why he's an Olympic champion. He's very passionate about everything. I love poker, he loves poker," Dannenmann said. "Everything he's done, he does all out."