NEW YORK (CBSNewYork) – A disheveled looking David Laffer pleaded not guilty Thursday on first-degree murder charges in the shooting deaths of four people at a Medford pharmacy on Sunday.

PHOTOS: Haven Drugs Pharmacy Massacre

Assistant District Attorney John Collins called the shootings “the most cold-blooded robbery-homicide in Suffolk County history.” Laffer said nothing at his arraignment. His lawyer pleaded not guilty for him. A judge ordered Laffer be held without bail.

Assistant District Attorney James Chalifoux said that “in combination with trying to rob the store of various narcotics, he kept an eye on the front door. As the customers came into the store they were each executed, shot at close range — both from behind when they walked inside.”

1010 WINS’ Carol D’Auria reports: Courtroom Packed For Laffer’s Arraignment

Laffer’s wife, 29-year-old Melinda Brady, is set to be arraigned separately. She faces third-degree robbery and obstruction.

“He did it. He did all of this,” Brady said as she was being led into a police car at Suffolk police headquarters early Thursday morning. “He was doing it because he lost his job and I was sick. I’m sorry he did all of this.”

As her husband was being taken by police to his arraignment later in the day, he almost ignored reporters’ questions until asked if he knew that his wife had apparently implicated him in the murders.

“What did she say?” Laffer asked before being placed into a police car.

WCBS 880′s Mike Xirinachs reports: Laffer Looked Stressed And Confused Leaving For His Arraignment

“You guys are cowards and junkies and sorry doesn’t mean nothing,” David Taccetta, the brother of victim Jamie Taccetta, said.

Taccetta’s family followed Laffer to his arraignment and after the accused Medford murderer pleaded not guility, there was an outburst.

“I think he should rot in prison for the rest of his life,” David Taccetta said.

At Thursday’s news conference, Suffolk County Police Commissioner Richard Dormer said Brady drove Laffer to the pharmacy.

“Inside the pharmacy, Laffer shot two employees point-blank and two customers, executing the two as they walked into the store, shot them in cold blood, and then stole a large quantity of pain killers,” Dormer said.

Dormer said that the motive for the shootings was unknown and incomprehensible.

“This is very unusual. We found out that there was no criminal background with this individual and to suddenly engage in this type of violent behavior is beyond understanding. It doesn’t make sense,” Dormer said.

“Obviously, this was a brutal, execution-type slaying and who knows what could have occurred in future days,” Suffolk County Executive Steve Levy said at a news conference on Thursday.

Brady and Laffer were arrested Wednesday by authorities looking into the brutal murders of four people at the Haven Pharmacy in Medford.  They lived with Laffer’s schoolteacher mother, who has not been charged.

David Laffer and wife Melinda Brady (credit: Suffolk County Police Department)

Killed Sunday were store clerk Jennifer Mejia, 17, pharmacist Raymond Ferguson, 45, and customers Jamie Taccetta, 33, and Bryon Sheffield, 71.

Sunday’s killings stunned the Tri-State Area and prompted a massive manhunt for the suspect, who was caught on tape. The suspect was seen in surveillance photos wearing a hat and a black beard. Officials said Laffer was wearing a fake beard at the time of the massacre.

Levy said there was a number of pieces of evidence that led authorities to Laffer as their suspect. He said Laffer was a registered owner of a .45-caliber handgun, the same type of gun that was used in the murders.

Police said they went through a prescription list at the pharmacy which showed Laffer was a customer. Prosecutors said investigators also found Laffer’s fingerprints at the scene of the shootings on a piece of paper.

“Despite the defendant’s best efforts to wipe prints from the scene, that piece of paper was found on the ground near one of the victim’s bodies,” Collins said at Laffer’s arraignment.

Laffer was clean-shaven when he was arrested by authorities. He had a black eye and bruises, which police said were sustained when he resisted arrest.

“Laffer violently resisted police and his wife physically interfered with officers attempting to place him under arrest,” said Dormer.

Dormer said Laffer has not been cooperating with authorities.  The felony complaint outlined a combative Laffer, who lunged at officers and grabbed onto one of their guns while resisting arrest, the complaint said.

1010 WINS’ Mona Rivera reports: Dormer Says Laffer Has ‘Shown No Remorse’

Laffer was briefly hospitalized after his arrest. Dormer said Laffer and Brady were “obviously under the influence” of narcotics when cops arrested them on Wednesday.

Dormer said additional charges against Laffer and Brady may be forthcoming.

Police said Laffer, an Army veteran, went to the pharmacy to steal prescription drugs. The pharmacy was about a half-mile away from where Laffer and Brady shared a basement apartment in Laffer’s mother’s home at 30 Pitchpine Place.

WCBS 880′s Sophia Hall reports: Prosecutors Say Laffer Stole Numerous Containers Of Hydrocodone

“It was important to bring an individual into custody not only because we want justice done for those who were brutally slain that day, but also to provide a sense of peace of mind to the community,” said Levy.

Pharmacies in the area have been on high-alert since Sunday and Levy had a message for any would-be copycats.

“You’re going to get caught,” he said. “The videos are there. People are going to come forward to identify you. You are not going to be able to hide.”

Dormer said he hopes the arrests will bring some sort of closure for the victims’ families.

If convicted of the crime, what is the appropriate punishment in this case? Sound off in our comments section.