Nieves is being held without the right to bail after entering not guilty pleas to his new charges, including armed assault to murder, illegal weapons possession and kidnapping.
Judge Jacklyn Connly revoked Nieve's bail on an open domestic violence case and ordered him held without bail for 120 days after the prosecution and defense agreed to stipulate to having him considered dangerous.
According to investigators, Nieves is suspected of shooting the man near Ashley Reservoir in Washington. Police received a 911 call about 1 a.m. Tuesday reporting the shooting.
The victim was taken to Berkshire Medical Center, underwent surgery and was listed in critical condition.
According to the Berkshire District Attorney's Office, the victim has since been taken to another hospital and is still in critical condition. The name of the second hospital was not immediately available from the DA's office.
Details about the shooting were not available Wednesday because of records in the case having been sealed.
On Nieves' 18th birthday, April 19, 2017, he broke into his then-girlfriend's home through her bedroom window, yelled at her, punched a hole in a wall, pushed her onto a bed, broke a window on the front porch after he threw a mountain bike and pushed the woman to the floor before she got outside and called 911. Nieves told police he grabbed the woman, according to court files.
On Feb. 27, Nieves pleaded guilty to those charges, and his case was continued without a finding for six months, with the conditions that he not abuse the victim and complete anger management counseling.
According to court files, the morning of that plea hearing, another woman contacted police and said Nieves pushed her and grabbed her by the throat, leaving bruises on the side and back of her neck.
After the conclusion of his plea hearing, Nieves was arrested at the courthouse on a charge of assault and battery on a family or household member, according to court files.
That case remains open. Nieves was released on personal recognizance after his arraignment on that charge. That bail was revoked Wednesday, amid his new charges.
In all Wednesday, Nieves entered not guilty pleas to one count each of armed assault to murder, illegal possession of a loaded firearm, kidnapping, and assault and battery.
He is due back in court Sept. 20 for a pretrial hearing. He will be held without bail as dangerous until Dec. 21, at which point the matter of bail might be readdressed.
Investigators are asking anyone with information about the shooting to contact Massachusetts State Police Detectives at 413-499-1112.
Bob Dunn can be reached at email@example.com, at @BobDunn413 on Twitter and 413-496-6249.