A line of hundreds of mourners wrapped around the corner of the Smith Seaman and Quackenbush funeral home in Monroe on Thursday to honor the life of fallen NYPD Officer Brian Mulkeen.

"This is unbelievable. I know the police departments all stick together through thick and thin, and this is legitimate proof right here," said David McMillen, deputy supervisor of the town of Tuxedo police department. "It's an extreme brotherhood, sisterhood."

The New York City Department was joined by officers from Ramapo, Darien, Monroe, and Tuxedo — the department where Mulkeen began his career in law enforcement.

"What a great person, what a great soul, that's why we're here today — to recognize him and to console his family," McMillen said. 

Mulkeen was killed in the line of duty Sunday in the Bronx. A member of the borough's anti-crime unit, Mulkeen was trying to take an armed suspect into custody when he was hit by friendly fire. The suspect was also killed.

Mourners on Thursday wanted to focus on the life of Mulkeen, remembering his drive. 

"He started as a dispatcher and he wound up taking the test and going to the police academy because he always aspired to go to the NYPD — he met his goal for sure," McMillen said. 

Mourners also remembered Mulkeen for his sense of humor. 

"He was a jovial person, always smiling just always full of happiness. He was just a joy to be around and he kind of held everybody together," McMillen said. 

New York City Mayor Bill de Blasio was present to pay his respects along with Bronx Borough President Ruben Diaz, who talked about the sacrifice Mulkeen made for the safety of the city.

"We're all hurt, we're all mourning. We appreciate everything [Mulkeen] did for the borough and the least we can do is be out here and show support to the family and men and women in uniform," Diaz said.

NYPD investigators are still trying to piece together the chain of events that led to officer Mulkeen's death. Meanwhile, officials in Monroe are telling drivers to plan accordingly due to the increase in traffic in the area. 

Funeral services for Mulkeen will be held on Friday at 11 a.m. at the Church of the Sacred Heart in Monroe.