The battle over an overdose prevention site in Philadelphia is heating up. The nonprofit behind the proposed supervised injection facility picked up some unlikely support this week — from law enforcement. It also garnered some new local opposition.

Included in several friend-of-the-court briefs filed Wednesday in support of Safehouse was backing from more than 60 law enforcement officials across 13 states. Philly DA Larry Krasner, a longtime supporter, also signed his name among the current and former prosecutors standing behind the facility. Pa. Attorney General Josh Shapiro did not sign his name to the list.

Supporters’ central argument — that states should be able to open these sites as a public health measure — was echoed in another letter submitted by mayors from five U.S. cities from New York to Seattle.

Collectively, these briefs mark the largest showing of opposition against U.S. Attorney William McSwain’s high-profile legal challenge against Safehouse.

McSwain filed suit against the nonprofit earlier this year seeking to block its launch, arguing that it violates a federal law known as the “crackhouse statute” that prohibits any facility used for illicit drug use. Safehouse has countered that its Philly mission is a religious and medical imperative.

The feds’ side also picked up some support on Wednesday. In its first public statement on the issue, the Philadelphia police union signed a brief alongside several neighborhood groups which have long opposed the controversial facility. They maintain federal law is clear in prohibiting sites like Safehouse — and that they would attract more crime to already suffering neighborhoods.

Why cities and law enforcement are arguing in favor

In their separate briefs, the prosecutors, attorneys general and city leaders argued for state control over the issue of overdose prevention at a time when the opioid-fueled crisis claims more lives than homicide each year.

The main arguments put forth:

Congress has traditionally ceded control of medical efforts to state and local governments, the attorneys generals from D.C. and seven other states argued. The federal government’s blocking of Safehouse would “raise significant constitutional questions” about future intrusion on other state powers.

States must be able to “respond creatively to public health crises” when both the crises and the intervention efforts vary state by state, the attorneys wrote.

City leaders from Ithaca, New York City, Pittsburgh, San Francisco and Seattle say that their current methods to quell the overdose crisis have proven limited.

Those city leaders cited research that shows overdose prevention sites would save lives and promote access to treatment.

Opening a single facility would save local municipalities $1 million or more each year in emergency services for overdose prevention.

The local community and police union argument

Five community groups in the Kensington area — the epicenter of the city’s opioid crisis — won the buy-in the Fraternal Order of Police Lodge 5. The local police union, which represents some 14,000 current and retired officers, has been silent in the debate around Safehouse to date.

In support of McSwain’s push to declare the facility illegal, the groups collectively argued: