UPDATED: July 1, 2014, at 11:57 p.m.

A 23-year-old man was arrested last Friday on charges of aggravated rape and armed robbery in connection with an alleged sexual assault on the grounds of Harvard’s Arnold Arboretum in Jamaica Plain.

The man, Ashton Davis of Roxbury, pleaded not guilty when arraigned at the West Roxbury District Court Friday, according to the Suffolk County District Attorney’s Office.

Boston Police had responded to a call around 11 a.m on Thursday when a female college student unaffiliated with Harvard said she had been sexually assaulted and robbed at knifepoint within the arboretum grounds. The Harvard University Police Department did not respond to the crime scene, per an agreement with the city.

Davis was later apprehended with the assistance of a GPS bracelet that he had been ordered to wear in another pending sexual assault case opened in February, District Attorney’s Office spokesperson Jake Wark wrote in an email. The previous case “also involves a sexual assault on a lone female,” according to Wark.

Davis had been held on $25,000 bail until April, when the judge reduced his bail to personal recognizance at the petitioning of his lawyers, according to Wark. On Friday, Judge Mary Ann Driscoll set bail for the most recent case at $50,000 and revoked the previous bail, guaranteeing that Davis will be held for 60 days.

His next court appearance is set for July 29.

The Arnold Arboretum was established in 1873 as a public-private partnership between the City of Boston and the University, operating as both a botanical research institution and a public park. It is a National Historic Landmark and one of Frederick law Olmstead’s most well-preserved landscapes. The site houses a library and research facility, with a full-time staff of 75.

According to Jon M. Hetman, director of communications for the arboretum, the Boston Police Department is responsible for the facility’s security under an agreement between the University and the city.

“We were horrified to learn that a visitor to the Arnold Arboretum was assaulted on the grounds in Jamaica Plain last Wednesday morning,” Hetman wrote in an email to The Crimson.

—Staff writer Ivan B. K. Levingston can be reached at Ivan.Levingston@thecrimson.com. Follow him on Twitter @IvanLevingston.

—Staff writer Tyler S. Olkowski can be reached at tyler.olkowski@thecrimson.com. Follow him on Twitter @OlkowskiTyler.