JOHNSTOWN — The Clearfield woman who died Oct. 4, 2019, when a bomb exploded in her apartment received what she described to a neighbor as a “weirdo creepy scary box” that she was afraid to open.

But before the neighbor left her residence to go to Shawna L. Carlson’s apartment at 325 E. Market St. to take a look at the box, the woman said she heard and felt the blast of an explosion.

“I looked out my window,” the neighbor told a jury in U.S. District Court on Wednesday.

Surveillance video from a nearby business showed a ball of fire blasting through Carlson’s first-floor bedroom window, followed by heavy smoke and flames that engulfed and destroyed the structure.

A few hours later, emergency responders found Carlson’s body within the charred debris.

The jury watched that video in court on Wednesday while U.S. attorneys Maureen Sheehan-Balchon and Shaun Sweeney began building a case against Clint Addleman, 49, Morrisdale, who is on trial in connection with the 34-year-old Carlson’s death.

Addleman is charged with conspiracy to destroy property by explosive or fire, malicious destruction of property resulting in death and possession of an unregistered destructive device. He also is accused of conspiracy to distribute methamphetamine.

Investigating officers maintained that Addleman, in 2019, was running a drug-selling operation in and around Clearfield County. And based on testimony from a co-defendant’s trial in August, Addleman was pressuring Carlson to repay a drug debt of $800 and she was scared of him.

Co-defendant Kris Joseph Nevling, who was convicted in August and awaits sentencing, was described at his trial as being capable of building a bomb and doing so at Addleman’s direction to resolve a drug debt.

In Addleman’s trial, prosecutors are trying to convince the jury that Addleman is the mastermind behind the bomb that killed Carslon.

In court Wednesday, Clearfield Police Sgt. Daniel Podliski told the jury that as part of his investigation, he found Nevling a few days after the explosion at a residence two blocks away from Carlson’s apartment.

Podliski told the jury that when he stopped at the residence, he saw pieces of electronics that had been taken apart, wiring and tools.

“I believe they were parts for a bomb,” Podliski told the jury.

Addleman, represented by defense attorneys Frank Walker II of Clairton and Daniel H. Goldman of Alexandria, Va., has taken the position that there’s no evidence linking him to the bomb.

In cross-examining Podliski, Walker asked for confirmation that the officer went to speak to Nevling and saw items at Nevling’s residence.

“Not Mr. Addleman’s?” the defense attorney asked.

The sergeant said that was correct.

Prosecutors relied on additional witnesses to make connections between Addleman and the “weirdo creepy scary box,” including one who said the box was decorated with stenciled lettering, the same kind of lettering that Addleman’s sister, Emily, was known for using in craft projects.

The stenciled letters on the box sent to Carlson — as captured in a cellphone photo that Carlson sent to her neighbor before the explosion — showed messages that included “Sorry it took so long” and “I rec a message for you. Play it.”

Retired Bureau of Alcohol, Tobacco, Firearms and Explosives special agent Matthew Regentin told the jury that he had no doubt that the box delivered to Carlson’s residence contained an explosive device that detonated. Residue on pieces of black plastic, collected from the site of the bomb blast, tested positive for common explosive compounds, Regentin said.

Prosecutors also called in a state prison inmate who told the jury that Addleman admitted last year to being the one responsible for Carlson’s death and referring to Nevling as a “snitch.”

“(Addleman) said he made the bomb and that Nevling just had to deliver it,” the inmate testified.

The inmate also told the jury that when he talked with Nevling, Nevling told him the same story.

Under cross-examination, Walker asked the inmate about having heard confessions from two additional inmates for use in their cases.

“So you want this jury to believe that you magically got a confession from Clint Addleman?” the defense attorney asked.

“It’s the truth,” the inmate said.

U.S. District Judge Stephanie Haines, who initiated Addleman’s trial on Monday with jury selection, advised jurors that the case is scheduled to last through March 27.

Prosecutors indicated in court that they would be calling as many as 40 witnesses. Based on court documents, they are expected to include witnesses who will testify about Addleman’s repeated contact with Carlson and her fear of being harmed.

Defense attorneys, during jury selection, offered a list of 20 potential witnesses.

Mirror Staff Writer Kay Stephens is at 814-946-7456.