MILFORD — Delaware State Police said Thursday a man allegedly displaying a handgun went into cardiac arrest after a trooper deployed a Taser while attempting to serve a warrant west of Milford last weekend.

Authorities said preliminary investigation found the incident occurred at 10:06 p.m. on Sunday when Dover Police Department requested Delaware State Police to conduct a warrant attempt for a wanted man.

Milford resident Richard Wilson, 36, was sought at a residence in the 600 block of Milford-Harrington Highway, police said. Dover police had a pending warrant for Mr. Wilson for a criminal contempt of a domestic violence protective order (violation of protection from abuse order).

Upon arrival at the residence, police said, an unknown black man was seen inside. The man, later identified as Lionel Waters, 35, of Milford, would not provide any information about his identity or allow troopers access to the residence, police said.

Troopers then began to leave the property and the man opened the front door and said he had a weapon, according to police. Troopers demanded Mr. Waters drop the weapon, police said. Troopers saw what appeared to be a firearm in his possession, officials said.

According to police, troopers made numerous requests for Mr. Waters to drop the firearm, but he refused to comply. Mr. Waters then became agitated, aggressive and actively resisted arrest, authorities said.

A trooper then deployed his Taser and was unable to take the suspect into custody, police said. Fellow troopers assisted in taking Mr. Waters into custody as he continued to actively resist arrest, state police said.

Troopers requested an ambulance to respond in reference to the Taser deployment, police said. Assisting troopers collected and secured the firearm.

Mr. Waters went unconscious at the scene and it was at this point that troopers realized he had gone into cardiac arrest. They immediately began administering CPR and additional life-saving efforts until paramedics arrived, authorities said.

He was transported to Milford Memorial Hospital and is currently listed in stable but critical condition.

Mr. Wilson was later taken into custody as he arrived at the residence several hours later. Mr. Wilson was turned over to Dover police in reference to his outstanding arrest warrant.

No troopers were injured.

According to authorities, the Delaware State Police and the Attorney General’s office are reviewing the incident and charges are pending against Mr. Waters.