A Riverhead mother and son were arrested Friday night in two separate incidents involving knives, Riverhead Police said.

Beatrice Thomas, 73, was arrested at her Lewis Street home about 7 p.m. after a domestic dispute in which she cut her son with a knife, authorities said.

Ms. Thomas’s son, 53-year-old Colin Woodley, told police his mother “chopped” him with a knife, and he showed officers a laceration on his right forearm. When Mr. Woodley realized his mother was going to be arrested, he refused to assist with the police investigation, police said. Ms. Thomas was charged with second-degree menacing.

Mr. Woodley was then involved in an altercation on Doris Avenue in Riverhead about two hours later, during which he threatened another woman with a knife, police said. The victim told police Mr. Woodley shouted “I’m sick of this, I’m gonna cut you,” while brandishing a knife, according to a criminal complaint filed in Town Justice Court.

It was not clear if the two incidents were related. No one was seriously injured during either incident. Mr. Woodley was charged with second-degree assault.

• Alvaro Avarcon, 26, of Jamesport was arrested on DWI charges about 4 a.m. Saturday, town police said. He pleaded guilty to the charge and is being held at the Suffolk County Jail, according to court records.

• A Riverhead man was arrested Friday after damaging a second story window of Tweed’s Buffalo Bar and J.J. Sullivan Hotel on East Main Street in Riverhead Friday, police said.

Erick Nolan, 38, was charged with fourth-degree criminal mischief after a witness said he saw him damage the window. Police said the value of the damaged property was about $200.

• A Riverhead man was arrested last Thursday for violating an order of protection, town police said.

Authorities were called to a Doctors Path house after a 911 caller informed police of loud arguing going on at the property. When police arrived, Anthony Calloway, 34, and a female acquaintance were outside the home and told police that nothing was wrong.

Upon further investigation, it was learned that Mr. Calloway had violated a stay-away order by being at the house, police said. Mr. Calloway was charged with second-degree criminal contempt.

• Someone illegally dumped garbage on the Wells family farm on Sound Avenue in Northville last Wednesday. The trash included a refrigerator, rugs and numerous garbage bags. The incident was reported about 9:30 a.m. No charges have been filed.

• A Calverton woman was knocked to the ground after a dog bit her pant leg while she was jogging near her home, according to police reports. The woman refused medical attention and declined to press charges against the dog’s owner.

Those who are named in police reports have not been convicted of any crime or violation. The charges against them may later be reduced or withdrawn, or they may be found innocent.