The arrest of a protester over the weekend raised concerns and has led to calls for the Mayor's resignation.By Lindsay Ward

PITTSBURGH (KDKA) — The arrest of 25-year old Matthew Cartier over the weekend fueled protesters to march through several Pittsburgh neighborhoods — ending at Mayor Bill Peduto’s home where they demanded answers.

Overnight, KDKA learned who is now representing the man who was arrested.

Defense Attorney Lisa Middleman is representing Cartier.

She was once an Allegheny County District Attorney candidate.

On social media, Middleman called his arrest ‘dangerous and unconstitutional.’

She went on to say, “If we are to have any meaningful dialogue about the future of policing in this city and county, a better effort must be made to address the concerns of the community.”

Cartier’s arrest over the weekend sparked outrage and led protestors to calling his arrest a ‘kidnapping.’

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On Sunday, close to 200 protesters gathered outside of Mayor Bill Peduto’s home, where they chanted for his removal.

Video on social media showed police in street clothes take the 25-year-old man away in unmarked white vans.

(Photo Credit: Allegheny County Jail)

Police say Cartier was interfering with public safety, but protesters say police crossed the line and were using force to intimidate protesters.

City of Pittsburgh leaders held a press conference on Sunday to address questions and concerns that citizens had brought up.

Watch the full press conference below:

(Video credit: City of Pittsburgh — Mayor’s Office)

“We attempted to have the individual move his line of bikes approximately 25 feet to open up the intersection of Fifth ave and North Dithridge. We did this also due to move-in day for Pitt, so traffic was heavy,” said Sergeant Donald Mitchell from the Pittsburgh Department.

“He refused on several occasions, saying he doesn’t listen to the police and he didn’t care,” Mitchell said.

“No level of cooperation at all is going to lead to somebody getting hurt or somebody getting killed,“ said Pittsburgh Police Chief Scott Schubert.

Beth Pittinger, the Executive Director of the Independent Citizen Police Review Board in Pittsburgh calls what Public Safety described as a “low-visibility” tactic to make the arrest as “sneaky.”

Meanwhile, the Pennsylvania chapter of the ACLU responded, saying in part “Once again, police in Pittsburgh have shown why people are in the streets protesting for Black lives and against police brutality.”

The organization also criticized the Mayor, saying while they were consulted about police tactics, this is not what they were consulted about.

Cartier is facing charges of obstruction of a highway or other public passage, disorderly conduct, and failure to disperse.