Groton ― The victim of an assault Monday morning in a parking lot on Poquonnock Road has died of his injuries, Groton Town police said Wednesday,.

Police said the victim, Gerson Chiluisa, 46, of 2845 Park Ave., Bridgeport, died Tuesday evening at Yale New Haven Hospital in New Haven.

An autopsy performed at the state Office of the Chief Medical Examiner in Farmington certified the cause of death as “blunt force injury of head” and the manner of death as homicide, police said in a news release.

Groton Town police’s Criminal Investigation Division identified the suspect as Antwan T. Strickland, 31, of 47 Orange St., Hartford, who was arrested about an hour after the assault Monday at a nearby business. Strickland initially was charged with first-degree assault and second-degree breach of peace. He was arraigned Tuesday in New London Superior Court, where he pleaded not guilty and was held on a $750,000 bond.

Police said prosecutors will decide whether to upgrade the charges Strickland faces.

At 10:34 a.m. Monday, Groton Town police were called to an assault in the parking lot at 618 Poquonnock Road, a residential substance abuse facility owned by Stonington Behavioral Health Inc. Lt. Dave Miner said Chiluisa was unconscious when police arrived.

Miner said the investigation revealed that Strickland had confronted Chiluisa in the parking lot and struck him, causing him to fall to the ground. According to a police incident report, Strickland said he struck Chiluisa with his hand in the area of his nose, causing Chiluisa to fall backward and strike his head on the asphalt.

Stonington Behavioral Health staff told police they believed the suspect may have been Strickland, who “had just been kicked out” of the program, the police incident report stated. Police learned that both men had been involved with the behavioral health facility.

Chiluisa initially was taken by ambulance to Lawrence + Memorial Hospital in New London and then air-lifted to Yale New Haven Hospital.

Strickland was located about an hour after the assault at Sneeker’s Café, a short distance from the behavioral health facility. Officers took him into custody at approximately 11:30 a.m. without incident.

During his arraignment Tuesday at New London’s GA 10 Courthouse, Strickland was appointed a public defender, Kelly Goulet, who was unavailable to comment Wednesday afternoon.

Strickland was ordered to undergo a mental health screening and was placed on suicide watch, according to court documents.

Even before the victim died, court records show, Strickland’s case was being considered by the court for possible transfer to New London Superior Court’s Part A docket, where the region’s most serious cases are heard.

Strickland has a long criminal history, with convictions that date back to 2016, court records show. He has convictions for crimes ranging from sexual assault and burglary to interfering with police and trespassing, with periods of incarceration from 30 days to two years in prison.

He most recently appeared in Bridgeport Superior Court last week on a third-degree assault charge in connection with a March 18 incident. He was released on a promise to appear in court.

c.bessette@theday.com

Day Staff Writer John Penney contributed to this report.