Police say an 18-year-old used a lighter to ignite his hat and a lawn sign and threw the lit items into the woods Friday night near the sump on Plainview Road and Dorothea Street.

The Nassau fire marshal tells News 12 this caused a small brush fire to break out.

Detectives say a 70-year-old man in his car witnessed the alleged incident.

According to police, the witness approached the suspect whom police identified as Jeffrey Neftaly Portillo, of Bay Shore, to try to get him to stop. At that point, Neftaly Portillo allegedly pulled out a knife, threatened the witness and said that he had a “piece” on him. Police say that the K-9 unit then came and searched the area and found the Neftaly Portillo and arrested him without incident.

“It’s a little scary to see a situation like this in Plainview where people are coming out and lighting fires,” said Phil Epstein, of Plainview.

Neftaly Portillo was charged with arson and menacing.

A neighbor who declined to talk with News 12 cameras says another neighbor ran out of his house with a fire extinguisher to fight the fire before crews got there and contained it.

Police say Neftaly Portillo was issued two appearance tickets.

He’s due to face a judge on April 14.