The man killed by Nassau County cops Tuesday night was strapped with enough ammunition to commit mass murder.

According to police, Jason Beller, a 31-year-old Commack resident, had an assault rifle strapped to his chest and ammunition strapped to his arms. He had five loaded weapons in his pickup truck, including a Tec-9 automatic pistol and an assortment of semiautomatic weapons. He was locked and loaded when his car slammed into a utility pole on Bellmore Avenue just before 10 p.m. Tuesday night.

From inside the wreckage, Beller fired at police as they arrived at the scene to help. He shot off eight rounds, hitting and critically injuring a young fireman whose unit had responded to the car accident.

“All the guns were readily available and loaded,” Nassau County Detective Michael Bitsko told Metro. “The two sleeves on his arms were loaded with ammunition and ready to go. The gun he was shooting with had a laser and it was pointed directly at a police officer.

“We have no motive and he can’t be questioned because he was killed,” he said.

Beller was from Florida and had been living in Long Island for a year.

His family told Newsday he was deeply troubled and apologized to the wounded firefighter.

Hero firefighter in ICU

After he was shot, Justin Agnell, a 20-year-old volunteer fireman was taken to Nassau University Medical Center, where he is making a full recovery in the intensive care unit.

“He is in stable condition and if he continues improving, he should be released today,” said hospital spokeswoman Shelly Lottenberg. “He’s had a lot of visitors — friends, family, firemen.”

“I’m still in ICU but I feel OK, just got up and walked around a bit,” Agnell posted on his Facebook page yesterday. “I’m still in shock this is happening.”