Two inmates arrested following a seven-hour standoff at a Butler house this week were held in a so-called “dry cell” at the Butler County Prison.

Authorities suspect one or both of the prisoners may have swallowed balloons or baggies filled with drugs before they were arrested Monday.

A third suspect already vomited up a “large amount of drugs”

at the police station soon after being arrested, Butler police Deputy Chief David Adam said Thursday.

City police, meanwhile, say they have recovered a handgun near where the standoff unfolded Sunday night and Monday morning in the 400 block of Franklin Street,

But it is not known if the gun, which had its serial number filed off, belonged to any of the four suspects arrested in the incident.

“We don’t know if it’s connected,” Adam said, “but we want to find out.”

Charged following the standoff were Joseph J. Bell, 23, of Pittsburgh; and Kenneth T. Henry, 40, Michael L. Jackson, 24, and Janeal Armstrong, 32, all of Philadelphia.

The four defendants — all convicted drug felons — are being held in the Butler County Prison on $100,000 bail each.

A woman who lives at the house that is divided into apartments called 911 just after 9 p.m. Sunday to report several men with guns had broken into her home.

City officers got there and saw a man coming out of a second-story window. The man, Adam said, appeared to have a handgun.

Police were able to get the caller out safely after the men went to a different apartment upstairs. No one was injured.

State police and several local departments were called in to help as officers surrounded the building. Authorities tried to speak to the suspects holed up, but they got no response.

Eventually, the Allegheny County SWAT team arrived to take over the operation. The impasse continued until about 4 a.m. when SWAT members fired tear gas into the building.

Moments earlier, police found Armstrong hiding in an alcove behind the house.

He was searched and found with suspected drugs, according to court documents, that included 31 stamp bags of heroin, two baggies of crack cocaine and three bags of marijuana. He also was carrying $700 in currency.

Police entered the house and found Bell, Henry and Jackson in the attic. They found no drugs on those three suspects.

No guns were found either, Adam said, after police searched all four defendants and the house.

At the station, while waiting to be interviewed, police said, Armstrong complained of not feeling well. He subsequently vomited into a garbage can.

What he expelled included packaged rocks of crack cocaine and glassine bags of heroin, Adam said.

Suspicious that the others could have swallowed drugs, police decided to have X-rays taken of all four defendants.

The examinations, authorities said, turned up several unidentified objects in the stomach of one suspect and one unknown object inside another one of the men.

Those two defendants were placed in the prison’s dry cell, where inmates can’t dispose of illicit drugs undetected. Guards use the cells to monitor the inmates at all times.

The prisoners did not have access to running toilets. Instead, they were provided with plastic urinals.

Eventually, correctional officers inspected any expelled waste for drugs.

“The use of dry cells is not common,” Warden Joe

DeMore said Wednesday, “but it happens when there’s suspicion that an inmate is hiding drugs.”

He would not comment on the status of the two standoff suspects who were being held in the dry cell.

Depending on what is ultimately found, the suspects could end up facing drug possession charges.

As of Thursday, Armstrong is the only defendant charged with possession of a controlled substance. Police charged him with both felony and misdemeanor possession.

Police could also file additional charges against the defendants, following lab tests of the gun recovered Tuesday near the house of the standoff.

A neighbor about 12:30 p.m. Tuesday reported finding the 9 mm pistol.

“It was in close proximity to the house,” Adam said. He declined to provide further details about where the gun was found.

Near the gun and also seized by police was a 9 mm magazine and one 9 mm bullet, and a loaded .380-caliber magazine.

In addition to aggravated assault, burglary, conspiracy, simple assault and reckless endangerment, Bell, Henry and Jackson are charged with felons prohibited from possessing firearms.

But, Adam conceded, police filed that firearms charge based solely on the victim’s eyewitness account. It’s unlikely that charge would prevail without physical evidence — namely, a gun.