A man who was in a struggle with police in Haverhill, Massachusetts Friday night has died, the Essex District Attorney's office said Saturday.

The 43-year-old man, identified by his family as Francis Gigliotti, had been "behaving erratically," according to investigators, on White Street just after 6 p.m.

Death of Francis Gigliotti 

Police said a caller told them Gigliotti was running in the middle of the street, hit a car with his head and kept running.

"Video surveillance shows the male weaving in and out of traffic, nearly being struck several times by passing motorists," D.A. Paul Tucker's office said in a statement.

Police found Gigliotti and called an ambulance for help. That's when they said he tried to run into the Bradford Seafood restaurant on Winter Street.

"Officers attempted to restrain the individual for safety purposes and for the safety of the surrounding public. The officers and male party ended up on the ground outside Bradford Seafood in a struggle," Tucker's office said.

"During this encounter, the male party became unresponsive, and first responders attempted lifesaving aid. EMS arrived moments later and transported the male party to a local hospital where he was later pronounced deceased."

Gigliotti's fiancée, Michele Rooney, said she arrived at the scene right as he became unresponsive. 

"That curdling scream like 'Help! Get off me.' And just seeing them all on top of him," Rooney said. "He's never acted out, erratically or violent and that's why I don't know what happened."  

"I think they should have approached him a little bit more easily and tried to calm him down."  

It's not clear yet how he died. 

A woman who runs the restaurant told WBZ-TV they had to have their customers leave through the kitchen in the back as a precaution.  

No other information is available at this point in the investigation, which includes the district attorney, Haverhill Police and the chief medical examiner. 

Haverhill mayor responds

Melinda Barrett, the mayor of Haverhill, posted a statement on Saturday.

"I want to offer my condolences to the family of Francis Gigliotti and assure our community that I am closely monitoring the circumstances around his tragic death," Barrett said. "The District Attorney's office is investigating. I promise complete transparency to our community and ask that everyone remain patient and calm as this investigation ensues and more information is made available."

Vigil held for Francis Gigliotti

Family members and friends held a vigil for Gigliotti outside the restaurant on Saturday night. They said that he was a wonderful man and was beloved by many.

"That was my partner, man, that was my friend, he was like a brother to me," Isaiah Dotson said. "It wasn't right and it ain't never going to be right, man, and we ain't never going to be the same man, we're hurting." 

"To see that on tape, I cried. You know I'm not going to lie, I cried because you know he's a good dear friend of mine and now he's gone," friend Daniel Gionne said.

His loved ones say he struggled with depression and other mental health issues. 

"He went through a struggle from losing his mom, losing his brother, being hit by a bus," Gionne said.

"He was just getting his life back together after all the hardship he's went through," his niece Albany Gigliotti said.    

A protest is planned for 1 p.m. Sunday at G.A.R. Park in Haverhill.