Bombers who killed Clearfield woman sentenced to life in prison in ATF-led, joint partner investigation

JOHNSTOWN, Pa. - A Bureau of Alcohol, Tobacco, Firearms and Explosives-led investigation resulted in Kris Nevling and Clint Addleman being sentenced in federal court to life imprisonment on their convictions of conspiracy to maliciously destroy property by explosive or fire and possession of an unregistered destructive device in relation to a targeted bombing that resulted in the death of a woman who owed one of the defendants a drug debt.

The apartment building after the fire was extinguished.

"Kris Nevling and Clint Addleman are brutal murderers," said Eric DeGree, special agent in charge of the ATF Philadelphia Field Division. "Together they staged a deadly explosion to try to hide their crime. Working methodically with our federal, state, and local partners, and applying ATF's unique forensic tools, we exposed their conspiracy and they now face long sentences in federal prison for their crime."

"Clint Addleman and Kris Nevling callously took the life of Shanna Carlson-someone who Nevling later testified in court was among his best friends-in one of the most violent and brutal manners imaginable, all over a small drug debt," said United States Attorney Rivetti. "They were convicted of their crimes by two separate juries. Today's sentencings ensure that Addleman and Nevling will both spend the rest of their lives in prison for their ruthless, violent conduct. Our office remains resolute in working closely with our law enforcement partners at the local, state, and federal levels to prosecute those who seek to commit such heinous crimes in our communities."

United States District Judge Stephanie L. Haines imposed the sentences on Clint Addleman, 49, and Kris Nevling, 49. The defendants were found guilty of the crimes through separate jury trials in August 2025 (Nevling) and March 2026 (Addleman), with the jury also finding Addleman guilty of malicious destruction of property by explosive or fire resulting in death and conspiracy to distribute methamphetamine. Both juries also determined the death of the victim-34-year-old Shanna Carlson, who was also known as Shawna-to be a result of the commission of the conspiring to maliciously destroy property by explosive or fire offense and, in Addleman's case, the malicious destruction of property by explosive or fire offense.

The evidence presented during the trials established that, in and around early October 2019, Addleman and Nevling aided and abetted one another in the construction and possession of a destructive device-a bomb-which was subsequently concealed inside a package addressed to Carlson using her nickname. At approximately 4:30 a.m. on October 4, 2019, the package containing the bomb was delivered and left outside of the door to Carlson's first floor apartment in a multi-unit rental property on East Market Street in Clearfield. Later that morning, the bomb detonated inside Carlson's apartment, killing her and causing a fire that destroyed the building. Trial evidence established that the victim owed Addleman an outstanding drug debt of approximately $1,000.

The ATF-led the investigation together with the Clearfield Regional Police Department, Pennsylvania State Police, and Allegheny County Sheriff's Office. Assistant United States Attorneys Maureen Sheehan-Balchon and Samantha A. Stewart and Special Assistant United States Attorney Shaun E. Sweeney prosecuted this case on behalf of the government.

ATF protects American communities from violent crime driven by the illegal use of firearms, explosives, and acts of arson. Through crime gun intelligence, forensic analysis, and relentless investigation, we identify and arrest violent offenders and gang members, dismantle trafficking networks, and sever the supply chains arming cartels, prohibited persons, and terrorist organizations. We defend the rights of law-abiding citizens by safeguarding lawful commerce and upholding the Constitution of the United States.

Learn more about what ATF is doing to reduce violent crime in your community:
@ATFPhiladelphia on X.