Adonias Estrada-Sinay, of Riverside, charged after alleged machete attack leads to 8-hour standoff with police

A Riverside man barricaded himself inside an apartment Friday after allegedly slashing another man in the head with a machete, leaving him “covered in blood,” Southampton town police said.

Adonias Estrada-Sinay, 35, of Riverside, was arrested more than eight hours after police arrived at the scene of the 3 p.m. attack on Pine Street. Officers were responding to a 911 call reporting a man assaulting another man with a machete, police said.

The Southampton Town Emergency Service Unit, New York State Police and hostage negotiators from both departments assisted in the arrest at 11:33 p.m. and town detectives obtained a search warrant with the help of the Suffolk County District Attorney’s Office, town police said.

The 24-year-old victim was transported by Flanders Ambulance to Peconic Bay Medical Center in Riverhead for treatment of a head wound, according to a news release. An update on his condition was not available Sunday.

Estrada-Sinay was charged with assault, menacing and criminal possession of a weapon, according to police. He pleaded not guilty at an arraignment in Southampton Town Justice Court on Saturday and was remanded to the county jail after a judge set bail at $50,000 cash, police said.

Southampton detectives are asking any witnesses to the attack to call them at 631-702-2230 or the department’s crime hotline at 631-728-3454.

By Grant Parpan

grant.parpan@newsday.com@GrantParpan

Grant Parpan covers Suffolk County courts and federal courts for Newsday. A Long Island native, he joined Newsday in 2022.