Zabin said that Markoff drew the gun, ordered the victim to the floor, forced her to her stomach and bound her arms with plastic ties. Markoff allegedly donned leather gloves during the attack and disabled Brisman's cell phone.
He then allegedly shot Brisman three times in the chest and stomach from close range, killing her almost instantly, according to the indictment.
Brisman was found by authorities with one flex-cuff restraint on her wrist and bruising on her other wrist. Zabin said that surveillence video of Markoff shows that he wore the same outfit -- a baseball cap and a button down t-shirt -- on April 10 and 14.
Police identified Markoff as the suspect by tracking the e-mails that were sent to Brisman to set up the meeting, according to a statement released by the prosecutor.
They used the Internet protocol address for the e-mail account to determine the physical adress from which the e-mails were sent, and when they staked out the location, saw a person who matched the description they had of the alleged assailant. That person turned out to be Markoff, the statement said.
When they learned he was a student at Boston University's medical school, investigators contacted university police to get a copy of his school identification photograph. When they showed that photo to the Las Vegas woman who had been robbed, she identified him as the man who had attacked her, according to the district attorney's statement.
Markoff allegedly used disposable Tracfones to contact the women. Calls can be made on the phones without the cellular company being able to identify who made them.
At the time of his arrest, which was made as he and his fiance drove to Foxwoods Casino in Connecticut on paril 20, Markoff had the same Tracfone used to call Leffler, the woman he allegedly attacked on April 10, with him.
Before his arrest in connection to the murder and robbery, Markoff had been a second-year medical student at Boston University.
In late April, a law enforcement source told ABC News that police found 16 pairs of women's panties in the Markoff's home. Four pairs of these panties were found inside rolled up socks that were hidden in the box spring of Markoff's bed that he shared with his fiancee McAllister in his Quincy, Mass., home.
McAllister and Markoff had planned to wed in a lavish August ceremony, an event that has since been called off, according to sources.
Authorities said that extra ammunition was also found at the scene.
McAllister had stuck by Markoff from the beginning, starting with her e-mail to ABC News shortly after his arrest saying her fiance "could not hurt a fly."
Along with the panties was a large bag with roughly 60 pairs of plastic flex-cuff restraints, the law enforcement source said.
The panties and restraints were found along with duct tape next to a hollowed-out copy of "Gray's Anatomy" that hid the semi-automatic weapon police believe was used to shoot Brisman April 14. Brisman had rented a room at the upscale Boston Copley Marriott from Monday, April 13, through Wednesday, April 15, to offer $200 massages "with hand relief."
Around the time of his April arrest, Markoff told his parents, brother and sister-in-law during a jailhouse visit to "move to California and forget about him,'' a law enforcement source told ABC News.
Guzman, Brisman's mother, wrote a statement that was read by a family spokesperson at the end of the arraignment.
"Julissa inspired family and friend, the loss to us is immeasurable," said the statement. "We are overhwlemed and devastated by the loss of our Julissa. She was a college student who would have graudated for counseling in May she had a good spirit and a dedication to helping others. We ask for privacy and compassion."
Suffolk County District Attorney Daniel Conley told Guzman in Spanish, "We will do everything we can for you."