UPDATE, 9/13/13, 4:50 p.m. EDT: Information on a motion to intervene filed Wednesday by DLA Piper on behalf of the Sergeants Benevolent Association has been added to the fourth paragraph below.

In the weeks since New York Mayor Michael Bloomberg's administration filed a motion to appeal a federal court judge's ruling that the New York Police Department's stop-and-frisk practice violates the constitutional rights of citizens—and requested that the court halt the implementation of a series of police reforms until the appeal is decided—at least three Am Law 100 firms have jumped into the controversial case.

At issue is U.S. District Judge Shira Scheindlin's August 12 decision that found stop-and-frisk violates both the Fourth Amendment prohibition against unreasonable searches and seizures and the Fourteenth Amendment's equal protection clause, because the policy disproportionately target blacks and Hispanics. Over an eight-year period, 83 percent of the police department's stops involved blacks and Hispanics, though members of those minority groups make up just about half of city residents. As part of the ruling, Scheindlin also issued a preliminary injunction against stop-and-frisk encounters that violate the U.S. Constitution, ordered reforms of NYPD policies and practices, and appointed a monitor from Arnold & Porter to oversee changes in the 35,000-officer department, sibling publication New York Law Journal reported at the time.

Several New York police unions, represented by Dechert, filed a motion to intervene in the case Thursday, saying, "These remedies will directly touch upon the rights and interests of the members of the NYPD, including rights subject to existing collective bargaining with the city of New York," such as training, supervision, monitoring, and discipline. The unions, including The Patrolmen's Benevolent Association of the City of New York and the NYPD Captains Endowment Association, say they represent more than 29,000 members of the police department.

Dechert's clients moved to join the litigation a day after another police union, the Sergeants Benevolent Association, filed its own motion to intervene along with with a motion to appeal the case. DLA Piper litigation partner Anthony Coles is representing the sergeants union—which says it includes 13,000 active and retired officers—along with DLA appellate partner Courtney Gilligan Saleski, who works from Philadelphia and Washington, D.C.

The four unions represented by Dechert specifically take issue in their 20-page filing with aspects of the reforms that would require police to write a narrative detailing the reason for each stop, saying it would be overly time-consuming and could result in hastily written reports that include errors. They also expressed concern over proposed changes such as requiring police to wear body cameras, saying such a change should be a matter of collective bargaining. In arguing for the right to intervene, the unions contend that they "can hardly rely upon the city to protect their interests in those proceedings."

The Dechert partners listed on the motion are Steven Engel, a former U.S. Supreme Court clerk and attorney with the U.S. Department of Justice’s Office of Legal Counsel, and James McGuire, a former New York state appellate court judge and chief counsel to then–New York Governor George Pataki. Engel referred all questions to a Patrolmen's Benevolent Association spokesman, who pointed to an organization press release citing Patrolmen's president Patrick Lynch as saying on behalf of the four unions involved, "The establishment of a federal monitor may directly impact our members’ safety, day-to-day responsibilities, and collective bargaining and other rights. So we believe that we should have standing to participate in arguing the appeal in order to protect those rights.”

On the opposite side of the case, Baker & Hostetler made an appearance last week on behalf of public advocate— and likely Democratic mayoral candidate—Bill de Blasio. In a letter to the court September 6, Baker & Hostetler partners John Siegal and Fernando Bohorquez come out against the city's stance, arguing that legal precedent in other cities shows that the remedies and police monitorship should be implemented even while the appeal goes on.

"Contrary to the city's contentions, the constitutional rights of New Yorkers should weigh heaviest in the court's decision whether to stay its remedies order," the brief says. They further argue that a stay of the order "will result in irreparable harm to the citizenry of New York by allowing the unconstitutional stop-and-frisk violations of untold numbers of people to continue, especially and disproportionately in communities of color."

De Blasio has been a vocal opponent of stop-and-frisk, releasing his own report in May denouncing the practice and pointing to the racial imbalance in the department's stats. (The plaintiffs in the case are being represented by the Central for Constitutional Rights, with pro bono assistance from Covington & Burling.)

Bohorquez said Thursday that the firm took on the assignment pro bono because of his ties to De Blasio's general counsel, former Orrick, Herrington & Sutcliffe associate Steven Newmark. The two worked together through Lawyers for Obama on fund-raising and voter protection efforts in both the 2008 and 2012 campaigns, Bohorquez says, and have been in talks about Baker & Hostetler working for de Blasio since Newmark moved into his new position about a year ago.

Civil rights cases are "near and dear to my heart," says Bohorquez, who is a board member for Latino Justice and has previously served as chair of the civil rights committee for the New York State Bar. "I do them on whatever down time I find."

Siegel, a former Capitol Hill aide to then-congressman Charles Schumer and chief speechwriter for New York Mayor David Dinkins, says he's known de Blasio for 24 years, since the pair worked together on Dinkins's 1989 campaign. "We don’t see this as even a close call on a stay," Siegal says. "We looked at precedents where federal courts have ordered outside monitorships for city police departments, and the precedents are very clear. The monitorship process goes forward pending any appeal." One of the cities they cited, New Orleans, selected Sheppard Mullin Richter & Hampton to serve in a police monitorship role earlier this year.

De Blasio isn't the only mayoral hopeful that Baker & Hostetler has been working for in recent months. As The Am Law Daily reported in 2011, Baker & Hostetler has advised former U.S. Representative Anthony Weiner since even before his sexting scandal first took hold.

The firm's representation has continued into this year. According to campaign finance records, Weiner paid Baker & Hostetler $4,125 for legal services in August (the records also show periodic payments totaling $21,047 dating back to September 2010). Siegal declined to comment Thursday on the firm's current work for Weiner.

When it comes to supporting the campaigns with donations, Siegal and Bohorquez have only lent their support to de Blasio, with Siegal giving a total of $1,500 and Bohorquez giving $1,100, according to finance records. Siegal did help raise money for Weiner's 2009 mayoral campaign, which ended when Bloomberg succeeded in extending the term limits, allowing him to stay in City Hall for another four years. Siegal says he advised both de Blasio and Weiner in opposing the term-limit extension. (Siegal also clashed with the city in another case that began last year, representing filmmaker Ken Burns in opposition of a subpoena by the city requesting that he turn over outtakes from his film, The Central Park Five, which would help the city defend itself against a lawsuit brought by five men convicted of a notorious 1989 crime.)

The entire stop-and-frisk appeal could become moot when Bloomberg leaves office in January. Even if the U.S. Court of Appeals for the Second Circuit approves an expedited schedule that the city requested, briefing would still extend into late January, according to court records.