AURORA, Colo. — An Aurora police sergeant who retired in 2006 is accused of helping the suspect of two pipe bombings in Aurora cover up the crimes, according to an affidavit.
Curtiss Howard Christensen, 69, has been charged with accessory after the fact to first-degree arson, tampering with physical evidence and unlawful purchase of firearms. He posted bond on March 5 for $75,000.
He is a former Aurora Police Department sergeant and retired in 2006.
On Christmas Day 2020 and Jan. 7, 2021, two pipe bombs were detonated in Aurora, damaging three homes. Nobody was injured.
Scott Campbell, 45, who is accused of detonating both bombs, was arrested in mid-January and faces charges of attempted first-degree murder, first-degree arson, and possession of a weapon by a previous offender.
Investigators learned that Christensen acted as an accessory after the act in connection to the incident on Christmas Day, tampered with physical evidence and knowingly provided or transferred two firearms to Campbell, who lived in his home with Christensen's family. Authorities said Christensen knew Campbell was a convicted felon, according to an affidavit.
The incidents happened in the following areas:
- 18200 block of E. Mansfield Avenue, Aurora (around 5:30 a.m.)
- 4630 block of S. Pagosa Circle, Aurora (around 4:45 a.m.)
Following the two explosions, authorities determined that the likelihood that somebody would get injured or killed was very high, and that the person responsible would likely continue to detonate the pipe bombs, according to the affidavit.
Investigators found that the components used to create the homemade explosives were similar, further solidifying their belief that they were created by the same person or people, according to the affidavit.
When looking at surveillance footage, authorities saw that a suspect lit the fuse for each device while driving and dropped it out of the driver's side window while the vehicle was still moving. The pipe bombs landed in the middle of the road in densely populated residential neighborhoods in each case, according to the affidavit. This meant that the suspects didn't control the direction of the bombs' end caps.
"Upon detonation in both cases, end caps from each device penetrated exterior residential walls and windows and traveled through homes in the area," the affidavit reads. "It is simply a matter of luck that persons inside these residences were not injured or killed by shrapnel or the endcap projectiles created by these explosions."
Authorities determined this meant that the suspect or suspects intended to injure or kill residents or were indifferent to the potential risk of injury, according to an affidavit.
Pieces of the bomb were brought to the Aurora Police Department Crime Scene Unit for lab and DNA analysis. On Jan. 15, the lab found that DNA on pieces of both pipe bombs matched and that the DNA profile matched one in the Colorado Offender Database for Campbell, according to the affidavit.
When looking at records, authorities determined Campbell lived on the 3500 block of S. Uravan Street in Aurora. An Aurora police sergeant had previously surveyed the area and noted that there was a covered trailer parked on the side of the residence, according to the affidavit.
Authorities also found a 2004 Nissan Pathfinder registered to Campbell's address and under the name Curtiss and David Christensen. The suspect vehicle in the bombings was described as a dark-colored SUV pulling a utility-type trailer, according to the affidavit. Investigators said they believed the Pathfinder and trailer were both involved in the pipe bomb incident on Christmas Day.
On Jan. 15, 2021, authorities served a search and arrest warrant at the home on Uravan Street. Campbell was arrested and evidence was recovered from the home, including:
- Components for bomb making
- Fuses
- Pyrodex (similar to black powder)
- Magnesium powder and billet
- Aluminum powder
- Handwritten notes describing device construction and performance of several reconstructed and detonated bombs
- Several firearms
In an interview, Campbell confessed to building and detonating the bombs. He was arrested.
His cell phone was seized as evidence.
At this point, investigators found information that indicated that Christensen, a former APD sergeant, was involved as an accessory after the fact in the Christmas Day bombing. They also learned that Christensen lived at the Uravan Street home, along with his wife, son and Campbell. His wife would later say that Campbell and the Christensens' daughter had dated and Campbell had fallen on hard times and moved in with them.
On the phone, authorities found texts between Campbell and Christensen in which they talked about parking the trailer and Nissan in separate places since the two together had been identified as being involved in the bombings. Christensen recommended not paying for a garage because of the paper trail, according to the affidavit.
In an interview with Christensen during the service of the search warrant, authorities learned that Campbell doesn't have a car, but occasionally drives Christensen's Nissan Sentra. Christensen said he used to own a Nissan Pathfinder but donated it to Step Denver between Christmas and New Year's, according to the affidavit.
Christensen told police that he wasn't sure who would have been driving the Pathfinder Christmas morning, but assumed it was Scott. When Christensen arrived home from work that day, there was a trailer hooked up to the car.
He also said he'd seen gunpowder in the garage but believed it was for Campbell, when reloading ammunition. However, authorities would later find that Christensen knew Campbell was a previously convicted felon and therefore prohibited from possessing firearms and ammunition, and should not be reloading. In addition, Campbell "had access" to Christensen's Glock.
During the search of the home, police found a "substantial amount of ammunition" in Campbell's bedroom, according to the affidavit.
In a recorded jail call between Campbell and Christensen's wife, she made comments that indicated her husband was aware Campbell was involved in the explosives, and that he'd known this before Campbell's arrest. At one point, she stated, "I really wish you would have gotten rid of everything when Curt said if the ATF gets involved..." This also indicated she was aware of Campbell's actions, according to the affidavit.
In addition, the fact that Christensen had allegedly told Campbell to "get rid of everything" is "telling," the affidavit reads. If he'd only been cleaning the firearms, there wouldn't be a need for ammunition in his room, the document continues. Investigators never found firearm cleaning kits or equipment during their search of the home.
"This message would be consistent with Curtiss Christensen advising Scott Campbell to destroy evidence of his involvement in the pipe bomb detonations before the ATF figured out Scott Campbell was involved," the document reads.
During recorded jail calls between Christensen and Campbell, authorities learned Christensen was living paycheck to paycheck and was short on funds. Investigators said it would seem unlikely he'd donate a vehicle — the Pathfinder — if he could instead sell it for money.
Investigators also discovered that Campbell and Christensen had talked in September and October 2020 about Campbell trying to acquire a rifle, but being unable to do so because he is a convicted felon. He asked for Christensen to help him. Evidence in this case indicated that Christensen purchased a Spike's Tactical ST15 rifle on Oct. 3, 2020 for Campbell, according to the affidavit. Christensen's wife confirmed this on Jan. 15 in an interview with police.
The two men also talked about purchasing large amounts of ammunition.
Based on all of this information, investigators determined that Christensen knew Campbell was responsible for the detonation of the pipe bombs and that those were criminal acts. In addition, evidence indicates Christensen attempted to conceal physical evidence (the Pathfinder). He is also accused of purchasing a firearm for a convicted felon.
On March 5, Christensen posted bond for $75,000.
