Residents from the community gathered and applauded when he confirmed the news.
Early said the obtained Colon-Ortiz's DNA from Marcotte's hand.
He thanked the murder victim because they wouldn't have got the sample if she hadn't fought back.
Early Jr said that a Massachusetts State Trooper saw a dark SUV in Worcester, similar to the one that was seen driving from the scene.
The man driving fitted a description of the suspect.
The trooper then went to the man's home, and eventually got a buckle swab DNA sample.
Test results which came in on Friday, the sample matched to DNA found on Marcotte's body.
Ortiz was then arrested. He is set to make his first appearance in court on Tuesday.
There was little information on the Ortiz. Early Jr said he was working near where Marcotte was killed on the day of her brutal death.
He has not formally been charged with her murder, but Early Jr said he expected it to come soon.
Ortiz has no criminal history. The DA was unsure whether he is a U.S. citizen.
In February, Early Jr said they had made a DNA breakthrough in the case.
He revealed they were looking for an average height Hispanic man.
He also likely had scratches or cuts on his face, neck, hands and arms that day, police said.
They added that they believe him to be the same man seen driving a dark coloured SUV in the area around the time that the young jogger was killed.
Police have not revealed how they acquired the DNA, saying only that they got it during the course of their investigation.
It is also not clear exactly how the DNA was used to build the profile.
Marcotte vanished on an afternoon run while on a visit to the home her mom Rosanna, lived in off Brooks Station Road. Marcotte lived in New York.
Her naked body was found at around 8.20pm in woodlands near the home.
She had been sexually assaulted, and her hands, feet and part of her head were burned.
It's believed she was killed some time between 1pm, when she left her mom's home, and 4pm.
Marcotte's shocking murder left her family shattered, they said in towards the end of last year.
Her uncle, Steven Therrien, read an emotional statement at a church in the town on December 31, asking for help finding the young woman's killer.
"It has been more than four months since Vanessa was tragically taken from us," Therrien said.
"Not a day goes by that we don't reflect on the enormity of our loss. She had already achieved much but we know she had much more to do.
"She was a loving caring intelligent young women who had her whole life ahead of her."
Marcotte's parents, Rossana and John Marcotte, stood silent next to Therrien at the news conference holding back the tears.
Her father held a banner that read "Justice for Vanessa."
And at Marcotte's funeral, her best friend, Leah Abrahams, have a moving eulogy to the girl that so many people loved.
"She was so perfect, it was otherworldly," she said.
"Something about Vanessa always reminded me of the ocean - so breathlessly beautiful, quiet and peaceful."
She later said: "You epitomise grace, light, humility, and absolute magic."
Marcotte was killed just weeks after Queens jogger Karina Vetrano was brutally raped and murdered while she was out for a run.
A suspect has recently been charged in connection with her death.
