Harvard and Cambridge police arrested a University custodial worker Tuesday night after he allegedly groped a graduate student at the intersection of Mt. Auburn and Holyoke Streets around 8 p.m.

Using footage from surveillance cameras, police arrested Geremias Cruz Ramos, 27, of Revere, Mass., around 10 p.m. Ramos is an employee of Harvard University Custodial Services in the Holyoke Center, according to Cambridge Police Department (CPD) spokesperson Frank D. Pasquarello.

This indecent assault, the sixth in four months in the Harvard Square area, is the only case for which an arrest has been made.

Police said Wednesday they have not yet determined whether Ramos is responsible for any of the other indecent assaults.

In this latest incident, the victim, a Harvard graduate school student, told police that the suspect groped her and casually walked away until he saw her call the police on her cell phone. He then fled toward the Holyoke Center, according to Harvard University Police Department (HUPD) spokesperson Steven G. Catalano.

When CPD and HUPD patrols arrived on the scene, officers searched the area for the suspect.

“Because we hired extra people in light of last two incidents, there were extra bodies on duty last night,” Catalano said Wednesday.

Because Ramos had fled in the direction of the tunnel that passes under University Health Services (UHS) from Holyoke Street to Dunster Street, police watched footage from surveillance cameras in that area, Catalano said.

“We got a pretty grainy shot of the offender where the offender was wearing a specific piece of clothing. HUPD recognized the clothing worn by a contract custodial person,” Catalano said.

The victim then identified Ramos out of a group of custodians that police had gathered from the area.

Ramos is an employee of Sodexho, a food and facilities management services company that Harvard outsources, according to Sodexho spokesperson Stacy Bowman-Hade.

Pasquarello said it makes sense that the suspect in this case is an individual who knows his way around the campus.

“We’ve had plain-clothes and uniformed officers out there,” he said. “We thought it was a strange turn of events that we were getting all these indecent assaults in the area. We kind of felt it was somebody very familiar with the area.”

According to Catalano, Ramos has confessed to Tuesday night's assault. Pasquarello said CPD is investigating whether Ramos is connected to the five other sexual assaults in the Harvard Square area over the last four months.

“We don’t know if they’re linked,” Pasquarello said. “We’re in the process of working with HUPD to take a look at some of these photos with the other victims. It takes a while to get people in.”

Pasquarello said he could not comment on whether Ramos has confessed to any of the other incidents.

A Harvard student was groped on Jan. 13 while walking on Mt. Auburn Street near Claverly Hall around 5:40 p.m.

On Jan. 10, a female undergraduate was “groped in the buttocks area” by a man on a bicycle around 9 p.m. in Harvard Yard, according to Catalano.

Around 7 p.m. on Dec. 11, a graduate student was walking toward Dunster Street when a man coming from the opposite direction allegedly attempted to grab her crotch.

On Dec. 2, an undergraduate was cutting through the parking lot of St. Paul’s Church on her way to Dunster House when an unidentified man attempted to rape her, according to HUPD.

And police said that on Oct. 22, a Harvard student was attacked in Cambridge Common at approximately 8:30 p.m. when a male grabbed her wrist and waist, spun her around, grabbed her breast and then attempted to remove her coat. The victim struck the face of the suspect, who returned the blow and fled the area.

Pasquarello said CPD will still have additional officers patrolling the Harvard Square area, and Catalano said no decision has been made about decreasing HUPD staffing levels at this time.

Sari M. Poage ’05, who said she found out about Wednesday’s assault from a Boston Globe reporter, said she felt “vulnerable” after this most recent assault and wondered why HUPD had not sent out a community advisory.

“I strongly feel that students should be alerted whenever their security is compromised by another assault...I guess is I wish I could get my news about my security at Harvard from Harvard, and not from a reporter,” Poage wrote in an e-mail to Mather-open, the House discussion list.

Catalano said that Tuesday night’s assault did not call for an advisory because the suspect was caught.

“We put out advisories where there is a continuing public safety threat,” Catalano said. “This incident didn’t require a community advisory because there was an arrest made.”

Bowman-Hade said on Wednesday morning she could not yet comment on Ramos’ specific assignment at Harvard.

But Poage wrote in her e-mail to Mather-open that she was concerned to find out that the suspect works at the University.

“The fact that this man was an employee of Harvard also greatly disturbs me considering the access custodians have with our rooms and the fact that it makes me wonder exactly just how safe we are around those that work around us.”

Willa H. Friedman ’05, who responded to Poage’s e-mail, said she thinks students have to be careful about the way they interpret the arrest.

“To publicize a newfound fear of custodians because of what one did wrong is inappropriate,” Friedman wrote in an e-mail to the Mather-open list. “We should respect them as individuals and be especially careful not to generalize about an entire professional group because of a single incident.”

Ramos was arraigned Wednesday morning and charged with one count of indecent assault and battery, according to Spokesperson for the Middlesex County District Attorney’s office Seth I. Horowitz.

Horowitz said that Ramos is being held for a “dangerousness hearing” to decide whether he can be released on bail.

Ramos will remain in the Middlesex County jail until next week’s hearing, Horowitz said.

—Staff writer Hana R. Alberts can be reached at alberts@fas.harvard.edu.