Days after three local men were charged with murdering a 22-year-old “Pit kid,” the regulars who congregate near the Harvard Square T-station mourned the woman they knew as “Rook” and complained that increased gang activity in the Square led to her death.

Police haven’t released the identity of the woman, whose body was found floating in the Charles River more than a week ago. But a Pit kid who identified himself as “Leppy,” and said he was her boyfriend said her name was Io Nachtwey.

Fellow Pit dwellers said she was originally from Hawaii, but lived in Maine before moving to Cambridge this summer with “Leppy,” whose nickname is short for Leprechaun. Friends said she was homeless, and often slept in cemeteries. Authorities have had trouble finding her family, Leppy said, because they have no permanent home and move frequently from place to place.

The woman was stabbed multiple times, beaten and thrown into the Charles River on Nov. 3, prosecutors said Friday at Boston Municipal Court, according to the Boston Globe. Her body was discovered the next day, near the Boston University (B.U.) Bridge.

On Friday, the Suffolk County District Attorney’s office arraigned Luis D. Vasquez, 19, of Lawrence; his homeless brother, Ismael Vasquez, 23; and Harold Parker, 27, of Mattapan on murder charges. Judge Charles Johnson ordered them held without bail.

Ana White, 18, of Milton and Lauren Alleyne, 17, of Malden were charged with accessory to murder and held on $50,000 bail. Prosecutors accused them of holding the victim down while the the other suspects stabbed her nearly 15 times in the chest, abdomen, back and arms. Prosecutors said she was also struck in the head with nunchucks.

Prosecutors are attributing Rook’s murder to gang violence, according to the Boston Globe’s account of Friday’s arraignment.

The Vasquez brothers and Parker, prosecutors allege, were involved in a plot to recruit area homeless people in to a robbery ring. Prosecutors said they organized a Halloween-night meeting at a Braintree hotel, during which they spoke to about 15 new gang recruits, including Rook.

They then instructed the group to steal items from around the Boston area as a prerequisite for gang membership, prosecutors alleged.

According to Leppy, the Vasquez brothers were once affiliated with the Latin Kings street gang, but decided to break away to form their own gang.

“They were renegade Latin Kings,” Leppy said. “They wanted to recruit homeless people. It was a power move.” The group was told to bring the stolen items back to the hotel within three days, prosecutors said, but the suspects kept Rook as an insurance policy.

When their recruits failed to return with loot on Nov. 3, the Vasquez brothers and Parker drove Rook around the Boston area to look for her friends, prosecutors said.

The suspects then allegedly drove Rook to the railroad tracks beneath the BU Bridge on the Cambridge side of the river, where they stabbed her to death and threw her into the water. Her body floated to the spot where it was discovered the next day.

The killing, prosecutors said, was intended to send a message to Rook’s friends.

By the time police linked the Vasquez brothers and Parkerto the murder, they were already in the custody of the Cambridge Police Department on kidnapping charges stemming from an incident that occurred only hours after the murder.

According to prosecutors, the three men drove to the Pit and forced one of Rook’s friends into a car.

The kidnapping victim’s girlfiend called the Cambridge Police Department at 10:46 p.m. and gave a description of the car, Cambridge Police spokesperson Frank Pasquarello said. About 40 minutes later, he said, a CPD officer spotted the car on Mass. Ave. and opened the door to find the victim, who was alone and unharmed.

An 18-year-old Pit regular with strawberry blond hair who identified himself as “Caos” claimed to be the man who was kidnapped yesterday.

He said he suspected there had been a murder as soon as the suspects forced him into the car.

“I saw the bloody knives,” Caos said. “It wasn’t my blood, so I knew it was someone else’s.”

Pasquarello would not confirm that Caos was the kidnapping victim.

Some Pit kids yesterday said Rook’s murder is an indication that gang activity is changing the atmosphere outside the T-station.

In addition to Parker and the Vasquez brothers, Pit kids said, a group of gang members who call themselves Crips started congregating around the Pit about a year ago.

Alex, 19, described the Crips as “kids trying to be bullies,” and said they’ve changed the Pit from a peaceful haven for hippie kids to a frightening place.

“Almost no one hangs out here anymore,” she said. “They’re all scared.”