Colon-Ortiz, a married father of three, is being held on $10 million cash bail in anticipation of his indictment for Marcotte's murder.
State Police search the woods August 9 for evidence after Marcotte was found slain.
Worcester Assistant District Attorney Jeffrey Travers said that mobile phone data shows that Mr Ortiz had been in that area on the date of the murder, and that he had not been working at the time.
The man charged with the attempted rape and deadly assault of last fall of Google executive Vanessa Marcotte is scheduled to be arraigned Tuesday in Leominster, Massachusetts west of Boston and authorities say murder charges will also be filed.
"His mind, and the minds of his fellow detectives, were always on this case", McKeon said, "and because of that we are in a position tonight to speak for Ms. Marcotte". Early added that additional charges will be added.
Scheduled to catch a 5:30 p.m. commuter bus in Boston back home to NY - where Marcotte worked as a Google account executive - her parents called the police when she did not return home. Her family called Princeton police when she failed to return home later that day, the Boston Globe reported.
Marcotte had gone for a jog near her mother's home when she was attacked, raped, murdered and her body set on fire.
Police said Marcotte's body was naked and partially burned. Investigators were able to recover DNA on her hands, which was sent for DNA testing.More news: US Intercepts Two Russian Bombers Off Alaska's Coast
Marcotte's cousins, Caroline Tocci and Steve Vittorioso, told ABC News they weren't surprised that the 27-year-old helped catch her own alleged killer by getting his DNA.
In February, police released a profile of the killer, who they described as light-skinned Hispanic man with an athletic build and average height.
Mr Ortiz was connected to the crime when an officer spotted a man fitting his description driving a black SUV, and later went to his house to ask for a voluntary cheek swab.
The suspect accused of murdering a New York Google employee in MA appeared in public for the first time since his arrest in the savage attack.
Colon-Ortiz pleaded not guilty to all charges.
And though investigators thanked the public for the more than 1,300 tips provided by the public, Early noted that Parr was the one who delivered the "break in the case".
The family has established the Vanessa T. Marcotte Foundation, which Tocci said promotes female safety awareness and aims to tackle the "societal issue. of the objectification of women" and reduce violence by promoting gender equality.