New York Cops: Serial Murder Gun Found in 'John Doe's' Duffel Bag Sources believe Salvatore Perrone, 63, may have planned to kill again.

Nov. 21, 2012 -- The man known as "John Doe Duffel Bag" was arrested today in connection with the slayings of three shopkeepers of Middle Eastern descent in Brooklyn, N.Y. -- and police believe he likely would have struck again if he hadn't been caught.

Salvatore Perrone, 63, was arrested following a long night of questioning by detectives.

Officials told ABC News that Perrone is being charged with three counts of murder. He has made admissions to police in connection with committing two of the murders but stopped talking before any discussion of the third, law enforcement sources said.

The murders took place in July, August and last Friday, Nov. 16. All three slain men were killed by .22 caliber slugs and one was stabbed as well as shot.

Police Commissioner Ray Kelly told reporters Wednesday evening that ballistics, a fingerprint and statements by the suspect linked Perrone to the crimes.

"NYPD homicide detectives today arrested Salvatore E. Perrone of Staten Island in the shooting deaths of three Brooklyn merchants after he made statements implicating himself, and after the .22-caliber rifle he used in the slayings was recovered from his duffel bag and subjected to ballistic tests," Kelly said.

"Those tests indicated that shell casings found at all three crime scenes were fired from Perrone's rifle. Perrone's fingerprint also was lifted from the murder weapon," he added.

Kelly added later that Perrone likely would have struck again.

Sources told ABC News that detectives canvassing the Brooklyn neighborhoods where the slayings took place discovered Perrone had approached at least one other shopkeeper.

In that instance, sources said, Perrone offered to sell the merchant a line of goods, complimented the man on his refurbishment of the store and asked if he worked alone. The man told Perrone he wasn't interested in his goods because he didn't carry the line Perrone was selling.

Perrone returned near closing time, according to sources, but customers appeared to have dissuaded him from carrying out any attack he might have intended.

Police later pegged Perrone as "John Doe Duffel Bag." That's the name they gave a then-unknown man carrying a duffel bag on video taken near some of the murder scenes. Now, police are pointing to the contents of that very bag as evidence Perrone committed the killings.

"When crime scene detectives searched the bag early this morning, they found the carbine with a sawed-off stock, and a combination laser-flashlight attached to its barrel with duct tape and two thick, pink rubber bands," Kelly said. "It had a single, live round in the chamber. They also recovered a box of 22-caliber long-rifle ammunition, an empty magazine and a 12-inch kitchen knife with dried blood on it. Detectives also found two Buck folding knives, each with seven-inch blades.

"Perrone was recognized yesterday [Tuesday] at a pharmacy in Bay Ridge, [Brooklyn], and voluntarily agreed to accompany responding officers to the station house," he said. "Detectives obtained a warrant to search Perrone's duffel bag, which was found at his girlfriend's apartment. It was the same bag that Perrone was seen carrying in videotaped images of him in the vicinity of the most recent homicide."

Perrone, a Staten Island resident and native of Bensonhurst, Brooklyn, has a rap sheet that includes stalking a former girlfriend and kicking in her door, burglary and driving while intoxicated on Staten Island.

The suspect had connections with the clothing business and possibly once had a clothing store, officials said. He reportedly carried merchandise in his duffel bag, law enforcement sources said.

Clothing or cardboard was used to cover the bodies of the murder victims, police have said.

A man, later identified as Perrone, was captured on video last Friday at 6 p.m. within a block and a half of the latest crime scene, a women's boutique on Flatbush Avenue. The latest victim, 78-year-old Rahmatollah Vahidipour, was killed sometime between 4:30 p.m. and 7:11 p.m. Friday.

A second video, from Aug. 2, appeared to show "John Doe Duffel Bag" near the Bensonhurst shop where Isaac Kadare, a Jewish man from Egypt, was murdered with the same .22 caliber gun that was used to kill Vahidipour, sources told ABC News.

On July 6, clothing store owner Mohamed Gebeli, an Egyptian Muslim, was killed inside Valentino Fashion in Bay Ridge. Gebeli was shot in the neck and was found with several pieces of clothing on top of him. Police said $383 in receipts was missing, but $1,500 was found inside a cabinet.

The trio of killings took place within a five-mile radius. Each occurred at a small shop that lacked security cameras, and each victim was over 50 years old and Middle Eastern, police said. It was not clear whether the victims had been robbed.

Police and prosecutors declined to discuss motives or any information the suspect might have disclosed during questioning.

Perrone will be arraigned within the next 24 hours and charged with murder in the first and second degrees for each of his three victims, according to the Brooklyn District Attorney's Office. The first degree murder charges apply under state law because three or more individuals were killed in the state in less than a two-year period under similar circumstances.

However, officials do not consider the severity of the charges crucial in the case because Perrone will turn 64 Thursday, so any conviction essentially will mean life in prison.

ABC News' Michael S. James and Kevin Dolak contributed to this report.