“These charges are very significant,” Assistant District Attorney Kristina Kerwin said during Davis’s arraignment. “I would suggest that this defendant, with the capacity to commit this type of crime, truly is a danger to anyone out in society.”

On Friday, Davis pleaded not guilty in West Roxbury District Court to charges of aggravated rape and armed robbery in the Wednesday assault. His bail was revoked in the earlier Roxbury case, and he was held on $50,000 cash bail in the arboretum attack.

Less than two months after a Roxbury District Court judge freed accused rapist Ashton Davis from jail over the objections of prosecutors, police say Davis raped and robbed a college student studying in the Arnold Arboretum on Wednesday morning — while he was still wearing his court-mandated GPS bracelet.


Davis, 23, of Roxbury, stood with a black jacket pulled over his head throughout the court proceeding. His lawyer, Thomas Karp, said his client denied the most recent charges and asserted that the Commonwealth did not appear to have probable cause in either case.

Prosecutors say Davis came at the young woman from behind with a knife, demanded her bag, and then assaulted her, telling her the attack could happen “in the woods or . . . right here.” She told police she waited about 12 hours to call 911 because she was scared and did not know if she wanted to report the attack.

Boston Police Commissioner William Evans said Friday he was upset that a man investigators worked hard to catch once was so quickly freed and able to prey on a woman enjoying a sunny day in the park.

“This poor girl’s life will be forever changed,” said Evans.

Davis was first arrested in February after police responded to a radio call for a rape in progress and arrived at Amory Street and Columbus Avenue to find a half-naked woman crying in a field. The woman told police she had been held down and raped by two men — one of whom she later identified in a photo array as Davis, according to court documents. The second man has not been identified, according to authorities.


Davis pleaded not guilty and was held on $25,000 cash bail, said Suffolk District Attorney spokesman Jake Wark.

He was released, according to Wark, while investigators were still gathering witness statements and phone records, and criminalists were testing physical evidence and expediting DNA analysis in order to obtain grand jury indictments so the case could be moved to Superior Court.

While waiting for the indictment, Davis’s defense lawyer, Aaron Lazar, in that case twice moved for bail reduction hearings and prosecutors twice objected, according to court documents.

The first time, in March, Judge David Poole denied the request. But the second time, on April 29, Judge Lisa Grant allowed it, releasing Davis on personal recognizance and requiring him to wear a GPS bracelet and undergo a mental health evaluation.

Prosecutors argued against his release.

“We opposed any reduction in bail that early in the case while the investigation was so active,” Wark said. “The facts of the case suggested a violent sexual assault by a stranger. That’s one of the most dangerous offenses we encounter as prosecutors.”

Evans said that too often, alleged offenders quickly wind up back on the streets.

“I don’t necessarily blame the judges. Maybe it’s overcrowding, maybe there’s other issues,” he said. “But I know, from a law enforcement standpoint, it’s very frustrating for my officers who work hard and put their lives in danger every day, only to see these kids back out in a couple days.”


A Trial Court spokeswoman said the Code of Judicial Conduct prohibits judges from publicly commenting on pending cases. Lazar did not respond to calls for comment.

What the prosecutor described on Friday as a “horrifying” attack began at 11 a.m. Wednesday, a little less than two months after Davis’s release.

According to Kerwin, the woman walked down a dirt path in the Arboretum, near a park entrance close to the Forest Hills MBTA station, to find a spot to study before her class.

Davis approached her, Kerwin said, threatened her with a kitchen knife, and took her cellphone, $10, and a CharlieCard. Then, still pointing the knife at her, he demanded sex.

Davis then sexually assaulted her, said Kerwin, and threatened her not to tell anyone, before fleeing on his bicycle.

Evans said investigators conducted interviews, viewed footage from area cameras, and examined physical evidence.

On Thursday, investigators downloaded data from Davis’s GPS bracelet, which brought the case together, Evans said, when it indicated he was in the area when the assault occurred.

“The totality of the evidence pointed to one suspect,” said Evans, who declined to talk more specifically about what evidence police have.

On Thursday, the victim picked Davis’s photograph out of an array and said it may be her attacker, Kerwin said.


In court on Friday, Davis’s lawyer said the identification was weak.

“The fact that she said it ‘may be’ my client is not probable cause,” Karp said.

He also questioned the accuracy of the GPS technology. Davis, he said, has no convictions on his record, is a high school graduate, and a longtime Boston resident.

“He indicates in no uncertain terms that he denies these allegations,” Karp said.

After the arraignment, two women who described themselves as family friends of Davis said he struggles with bipolar disorder and has not been taking his medication, but that he had not been acting unusual.

“He just helped me move some furniture Thursday,” said Lilly Johnson, who said she met Davis at The Home for Little Wanderers.

Aalilyah Nathan, 17, said that on Wednesday morning, Davis was angry and left to ride his bicycle as he usually did to calm down.

“He came back fine,” said Nathan. “He didn’t say anything. He just came back happy.”

Davis is due back in Roxbury District Court on July 29.

Globe correspondent Kayana Szymczak contributed to this report. Evan Allen can be reached at evan.allen

@globe.com. Follow her on Twitter @evanmallen.