On a quiet residential street in Clearwater, Fla., Geraldine Chasten made a point to look out for her elderly neighbor, Kathryn Schroepfor, checking in a few times a week and watching from her porch when anyone showed up at the door.

But she never imagined that anyone would deliberately harm the woman.

“I’m just at a loss to understand why somebody would do that to such a sweet old lady,” said Chasten, 73.

Neighbors of the 91-year-old woman who was beaten to death in a home invasion said they are glad to see police have arrested a suspect in the case — Dominic Panzino, 36, a Framingham resident who was nabbed by Revere police Wednesday after he fled to Massachusetts and stole a car from a rental center.

Still, these neighbors say, they struggle to understand how someone could have brutally attacked an elderly woman.

“It’s been a real shock to the neighborhood,” said Charlotte Michniewicz, who lives nearby.

Schroepfor’s body was found May 26 by her son, who is mentally handicapped, and the son’s caretaker. After Clearwater police scoured the scene, they believed Panzino — who was staying in the house next door, which was owned by his employer — was responsible for the killing.

Police allege Panzino fled Florida and drove up the East Coast with Schroepfor’s credit cards in a van he stole from the meat delivery company he worked for — a white 2007 Chevrolet Express, painted with black splotches to look like a cow.

Revere police said he is suspected of sexually assaulting a woman in Virginia along the way. Panzino ditched the van in East Boston, police said.

After that, Panzino and an accomplice, who police believe was Panzino’s brother, allegedly stole a car from a Thrifty Car Rental in Revere. The car’s back tires were punctured by the rental center’s security spikes, and Panzino was arrested by Revere police.

In Chelsea District Court Friday, Panzino was ordered held without bail and is due back in court Thursday.

Panzino agreed to return to Florida to face charges for murder and credit card fraud.

Before that can happen, however, authorities must decide whether to dismiss charges he faces in probation violations pending against him for convictions related to theft and burglary in Lynn and Malden district courts.

Panzino has a slew of criminal offenses in Massachusetts dating back to at least 1993.

In a 2008 court document, Panzino’s mother, Linda Miranda of Framingham, requested that the Malden court return the money she put up for bail for her son after he failed to appear for a court hearing. She explained that she needed the money to pay her bills, and to care for Panzino’s daughter, who was then 10 years old.

Chasten, Schroepfor’s neighbor, said Panzino had been living in the Clearwater house for a few months. She recalled the first time she saw him in the neighborhood.

“He was out in the street, pacing back and forth on the phone, yelling and screaming at somebody with his arms flailing,” Chasten recalled. “I thought, ‘Wow, that guy’s a real loose cannon.’ ”

Schroepfor, who lived alone, was one of the first residents in the neighborhood — she moved into her house just after it was built in the 1970s, Chasten said. Her husband died a decade ago. In addition to her son, Bobby, she had two daughters who live out-of-state.

The woman remained active, swimming laps at a local public pool well into her 80s.

She was quick to return favors, such as help operating her air-conditioning system, with sometimes quirky tokens: a box of Russell Stover chocolates or a bottle of Ensure nutrition milkshake.

Her son lived at a nearby group home, but she brought him home on weekends.

Carrie Dobraski, a waitress at the Three Coins restaurant in Clearwater, said Schroepfor and Bobby came to the restaurant every Sunday morning for lunch, always sitting in the same booth by the window, and ordering the same thing: two pancakes and a scrambled egg.

The restaurant was crowded on Sunday mornings, but Schroepfor always insisted that they didn’t mind waiting until things slowed down.

“They were the best customers you could ask for,” Dobraski said. “I can’t imagine what’s inside a person to make them do something like that.”

Chasten recalled having coffee at Schroepfor’s home last Mother’s Day.

The woman told her she was having a hard time dealing with constant loneliness. Chasten, who was about to retire from working at the Home Shopping Network, promised to help change that.

“I told her I was going to be retiring soon, and we could do some stuff together — see a movie or play Yahtzee or go to lunch,” Chasten said. “And now I can’t do that.”