Prosecutors accuse retired Aurora police sergeant of helping suspected pipe bomber hide evidence

AURORA | Authorities have accused a retired sergeant with the Aurora Police Department of helping an admitted pipe bomber cover his tracks after he detonated a homemade incendiary device in a residential neighborhood on Christmas morning, court documents released Wednesday show.

Aurora police arrested former APD sergeant Curtiss Christensen, 69, during a traffic stop near East Hampden Avenue and East Hampden Circle on March 3 for his suspected, ancillary role in a bombing at 18294 E. Mansfield Ave. in Aurora on Christmas Day.

Christensen, who retired from the Aurora Police Department in June 2006 following a 23-year career with the department, has since been charged with a trio of felonies: illegal purchase of a firearm, tampering with evidence and accessory to a crime, court records show.

A probable cause affidavit released Wednesday claims that Christensen assisted the alleged bomber, 43-year-old Scott Campbell, by helping him get rid of the car he used to transport the bomb and urging him to dispose of other evidence before authorities could seize it.

Investigators relied on extensive phone records, including recorded jail phone calls and captured text messages between Campbell and various members of the Christensen family, to solidify their accusations, the newly released arrest document filed against Christensen shows.

The document released March 10 details how Campbell allegedly constructed multiple pipe bombs using chemicals and plumbing equipment before detonating two of the devices near his residence on South Uravan Street in the early morning hours of Dec. 25, 2020 and Jan. 7, 2021.

Records show that Campbell, who has used the alias “Soupy,” texted a friend in the early morning hours of Christmas Day 2020: “I was thinking about maybe going to blowing some s*** up a little bit later want me to text you?”

At about 5:10 a.m. that morning, residential surveillance footage showed a car and trailer — both of which were later linked to Campbell — pass by the home of a 73-year-old woman, court documents show. The driver was seen dropping an object out of the vehicle’s window about 10 seconds before a large explosion sent shrapnel into the older woman’s front door and kitchen.

Ten days later, a nearly identical bombing occurred near 4632 S. Pagosa Circle, sending debris through a 28-year-old woman’s bedroom window. Additional surveillance footage obtained by police showed a driver dropping another ignited device out of a vehicle’s driver side window moments before an explosion.

The blasts damaged a total of three homes, though no injuries were reported, Aurora Fire Rescue reported in January.

“It is simply a matter of luck that persons inside these residences were not injured or killed by shrapnel or the end-cap projectiles created by these explosions,” Aurora Police Officer Andy McDermott wrote in his affidavit seeking a warrant for Christensen’s arrest.

About five hours after the first explosion, an apparent acquaintance of Campbell’s who lives several houses down from the blast texted him asking if he had been out late the night before, phone records show. The acquaintance told Campbell that police had been in the area that morning.

“I wonder how hard and how far they’re going to pursue that,” Campbell responded.

Shortly thereafter, Campbell texted Christensen, who was his landlord at the time, asking to help him hide Christensen’s own car and trailer “post haste.”

After initially agreeing to lend Campbell several hundred dollars for a temporary storage facility, Christensen then encouraged him to park the vehicle and trailer because “garage leaves a psprt ttail (sic),” according to the affidavit. Detectives later deduced Christensen had mistyped “paper trail.”

Police discovered that Christensen donated the car, a Nissan Pathfinder, five days later. They eventually alleged that constituted tampering with evidence.

Local and federal authorities later arrested Campbell at Christensen’s home following a SWAT team raid on Jan. 15. Court records show that Campbell was living at Christensen’s after he had “fallen on hard times.” He had previously dated Christensen’s daughter.

Police identified Campbell as the suspected bomber by finding his DNA on the metal explosive materials that shot through residents’ windows.

During his arrest, authorities found copious bomb making supplies in Campbell’s garage and bedroom, including gunpowder, magnesium and aluminum powder, hand-written notes outlining how to construct bombs, half-made explosives and an AR-15 rifle, according to court records.

Campbell has since been charged with eight felony counts, including attempted first-degree murder with extreme indifference, arson and possession of an incendiary device. He remains detained at the Arapahoe County jail in lieu of posting a $1 million bond, county records show.

Campbell confessed to detonating the bombs shortly after he was arrested and later wrote an apology letter to the homeowners whose residences were struck, according to court records.

Investigators later claimed that Christensen falsified several statements during his interview with police after Campbell was arrested. Detectives combed through multiple jail phone calls between Christensen and Campbell in which the former lamented the latter hadn’t disposed of implicative materials before authorities with the Bureau of Alcohol, Tobacco, Firearms and Explosives became involved.

“The fact that Curtiss Christensen had told Scott Campbell to ‘get rid of everything,” before the ATF got involved is telling,” McDermott wrote. “Curtiss Christensen is a retired Police Sergeant and would know, through experience, that the ATF is primarily responsible for investigating explosives and firearms charges. This message would be consistent with Curtiss Christensen advising Scott Campbell to destroy evidence of his involvement in the pipe bomb detonations.”

Police also accused Christensen of lying about purchasing Campbell an illegal gun last year. Christensen admitted that he knew Campbell was a convicted felon, and that he was not permitted to own a gun. He told detectives that the rifle found in Campbell’s bedroom was his, and that Campbell was merely cleaning it. Police found no firearm cleaning supplies on the premises.

Cell phone records indicate Christensen responded “absolutely” when Campbell asked him if he would buy him the rifle in September. After further conversation, Christensen responded again, saying “figure out where we goin & do some voodoo. I’m in.” He eventually bought Campbell the gun at a store in Parker on Oct. 3, investigators confirmed.

The night Campbell was arrested, investigators found the weapon hanging on a hook behind his bedroom door, “stored in a manner that is consistent with preparing for a quick deployment if necessary,” according to the affidavit.

Christensen’s wife also later told detectives that her husband had purchased the gun for Campbell, despite the latter’s inability to possess a firearm under state and federal law.

Campbell has a lengthy criminal history in Arapahoe County spanning more than a quarter century, according to Colorado Bureau of Investigation Records. He’s faced multiple assault, robbery and driving under the influence charges in jurisdictions across the metro area, records show.

He’s been sentenced to multiple stints in jail and prison in the past decade, including in 2009 for violating a restraining order and in 2011 for felony attempted robbery. His most recent jail sentence was handed down in October 2018 for a domestic violence charge related to harassing a person via strikes, shoves or kicks.

Christensen was released from custody two days after he was arrested when he posted a $75,000 surety bond, according to state court records.

He is set to appear next before Judge Melina Hernandez in Arapahoe County District Court at 1:30 p.m. on March 30. He has so far been represented by court-appointed attorneys from the Office of the Alternate Defense Counsel.

Christensen has never been listed as a defendant in another criminal case in Colorado, though the state Department of Revenue issued a distraint warrant against him in 2015 for some $6,300 in back taxes.

Hernandez in February denied a court motion filed by The Sentinel seeking the release of the affidavit filed for Cambell’s arrest. In a four-page ruling, she determined that the privacy of witnesses and victims superseded the public interest in the case and “disclosure of such documents would be imprudent at this stage of the proceedings.”

The Campbell record remains suppressed.

Campbell is slated to appear for a preliminary hearing in his case on March 18.