Police on Wednesday issued an arrest warrant for Mike Stratton, trial lawyer and former alder for Prospect Hill and parts of Newhallville, related to a domestic dispute at his apartment on Crown Street on June 13.

During that incident, Stratton, 48, was beaten by Courtney Darlington, a 20-year-old woman he had been dating, police said. Stratton later said Darlington began hitting him when he told her he wanted to end their relationship, adding that he did not resist, knowing that fighting back would make him culpable as well. He called the police.

Darlington was arrested and charged with assault and breach of peace. She was later released on a promise to appear in court. Stratton was not charged immediately following the incident.

Police announced on June 24 they were conducting a more thorough investigation of the incident, stating that that marijuana had been discovered in the fourth-floor residence when police went to secure the space. The announcement of the investigation came one day after Stratton had resigned his seat on the Board of Alders, citing family reasons and saying little more. He was six months into his first term and had emerged as a vocal critic of Mayor Toni Harp and what he characterized as the majority “voting bloc” of labor-backed alders.

Further investigation was required to find out “why any possible evidence of drugs hadn’t been seized as part of the investigation,” authorities said. New Haven Police Chief Dean Esserman also wanted to make sure officers had not afforded Stratton special treatment, Assistant Chief Archie Generoso said.

In a Wednesday press release, NHPD Spokesman David Hartman said new information uncovered in that investigation was presented to the State’s Attorney’s Office for review.

“Based on that review, an arrest warrant has been issued today for Michael Stratton for the charges of Assault in the Third Degree and Breach of Peace in the Second Degree,” Hartman wrote. Darlington faces identical charges.

No mention was made of findings concerning illegal substances, and Hartman did not elaborate on what evidence lead to the warrant. Reached by phone, he refused to discuss the evidence in what he described the “pre-trial phase.”

Generoso also would not comment on the nature of the evidence, but said it was “independent of both parties.”

“At the time of the incident, the officers that investigated did so properly,” Generoso said Wednesday afternoon. “This information was not available to them at the time. It was provided to us by neither Mr. Stratton nor Ms. Darlington.”

Darlington in fact told the New Haven Independent the day of the incident that Stratton had not hit her.

“Mr. Stratton did assault the young lady,” Generoso said. As for whether Stratton received special treatment during the initial police investigation, “that investigation is still ongoing,” Generoso said.

He added that authorities have asked Darlington to come in to give additional statements, but she has not responded.

Generoso said Stratton is not in police custody.