LEOMINSTER -- A driver who spotted an SUV that had apparently broken down on the side of Brooks Station Road in Princeton last August kept driving when he saw a man talking on a cellphone beside the vehicle.
He figured the man was already calling for help.
During that first pass, around 12:45 p.m., the SUV's hood was up. When the driver passed the Ford Escape on his return trip, the car's hood was down, the doors were closed, and no one was around it.
That chance encounter would gain greater significance when authorities asked for the public's help in solving the murder of Leominster native Vanessa Marcotte in woods off Brooks Station Road on Aug. 7.
That driver who passed the apparently disabled vehicle would be one of the 1,300 people who phoned in tips to state police regarding the case.
And that tip helped authorities to arrest Angelo Colon-Ortiz, 31, of Worcester late Friday on charges related to the murder.
Investigators would later trace Colon-Ortiz's cellphone back to the site where Marcotte's body was found around 8:30 p.m. on Aug. 7, Assistant District Attorney Jeffrey Travers said at Colon-Ortiz's arraignment Tuesday in Leominster District Court.
Colon-Ortiz is being held on $10 million cash bail after pleading not guilty to aggravated assault and battery and assault with intent to rape. Prosecutors expect to charge him with murder in coming weeks.
Members of Marcotte's family attended the hearing but left without speaking to reporters.
The suspect was arraigned while standing behind his defense lawyer, Edward Ryan Jr., inside a vestibule and out of view from many people sitting in the gallery.
Travers said Marcotte left her mother's Brooks Station Road house for a walk around 1:15 p.m. Scheduled to catch a 5:30 p.m. commuter bus from Boston to New York -- where Marcotte worked as a Google account executive -- her parents called police when she did not return home.
Investigators found Marcotte's body around 8:30 that evening partially undressed in the woods nearby. She suffered a broken nose and "crushing injuries to the structures surrounding her throat," according to court documents.
Her death was quickly ruled a homicide. Investigators fielded about 1,300 tips, including one from the witness who spotted the black SUV on the day of the murder.
An investigation continued for months, including a profile of the suspect from DNA evidence collected at the crime scene that suggested Marcotte's killer was a Hispanic or Latino man 20-30 years old.
The big break in the case came recently when Trooper Robert Parr of the state police detectives unit, spotted then jotted down the license plate number of a black Ford Escape SUV driven by a man who fit the DNA profile's description.
The trooper dropped by Colon-Ortiz's house to follow up on the tip, but the suspect wasn't home, according to court documents. Parr returned to the residence a second time, on March 16, when Colon-Ortiz voluntarily provided a DNA sample.
According to lab results that the State Police Forensic Laboratory released to detectives April 14, the DNA Colon-Ortiz provided matched samples collected from under the victim's fingernails, a break Worcester District Attorney Joseph D. Early Jr. at a Saturday morning press conference credited to the fierce fight Marcotte waged against her attacker.
The prosecutor said investigators traced Colon-Ortiz's phone to the time and place where the crimes occurred.
Colon-Ortiz was born in Puerto Rico and moved to Worcester in May 2016, said defense attorney Ryan. The United States citizen does not speak fluent English, Ryan said, yet within months of moving to the state he had a full-time job as a FedEx delivery driver.
He drove during 4 a.m.-to-11 a.m. shifts, including weekends, on delivery routes that familiarized him with the Princeton area, Travers said.
Ryan told reporters after the arraignment that because of a language barrier Colon-Ortiz may not have understood what he was doing when he submitted a buccal swab to investigators.
Ryan also voiced doubt that Trooper Parr's spotting Colon-Ortiz and his SUV was a random event.
"I just think either it's an incredible stroke of luck that a detective involved in the investigation just happened to be the guy to see the (SUV) as opposed to a police officer," Ryan said. "I mean, a black SUV driven by a Hispanic guy in Worcester?"
Colon-Ortiz is due back in court for a pre-trial hearing May 24.