HAMDEN, Conn. -- Police responded to a call of suspicious activity near the Helen Street area describing three men walking through residents' back yards.

Police said they saw two men, David Mills and Adrian Teddington, involved in a physical altercation. They said Teddington was holding Mills, who was incoherent and said he was on angel dust. The two men then engaged in a fistfight, police said.

Officers said they attempted to intervene and were able to separate the two, but Mills resisted their efforts by punching, kicking, and biting the officers. Officers said they called for backup at that point, and when Mills continued to resist, one officer used his Taser gun on Mills, police said.

It appeared that the Taser had no effect as Mills continued to struggle, officers said. As other officers arrived, Mills was eventually restrained, they said.

Mills was transported to Yale New Haven Hospital where he was pronounced dead approximately one hour after the initial incident.

An autopsy was performed at the Office of the Chief Medical Examiner in Farmington, medical officials said. The results of the autopsy are pending toxicology results, they said.

Teddington also resisted restraint, police said, and injured one officer by punching him in the face, police said.

When he was eventually placed into the back seat of the police vehicle, he attempted to kick out the windows, police said.

Medical assistance was rendered to Teddington due to his irrational behavior, police said. Officers said they believed that he was also under the influence of drugs and/or alcohol.

Teddington was taken to Yale-New Haven Hospital for treatment, officers said.

While at Yale-New Haven Hospital, Teddington broke free of his restraints and threatened to kill a police officer in the near future, police said.

Teddington, 26, of 34 Elizabeth St., West Haven, was arrested on three counts of assault on a police officer, interfering with an officer and threatening.

He was released from the Hamden Police Department after posting a $50,000 bond. He is scheduled to appear in court in Meriden on May 4.