By Brian Maass

AURORA, Colo. (CBS4) – Curtiss Christensen, a former Aurora Police Department sergeant, was arrested last week and charged with being an accessory to a crime and tampering with physical evidence in connection with a pipe bomb case in Aurora. Both charges are felonies.

Christensen, who retired from the Aurora Police Department in 2006, could not be reached Wednesday night via phone, text or email to comment on the pending criminal charges.

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Curtiss Christensen

(credit: Arapahoe County)

In a 37 page arrest affidavit obtained by CBS4, Aurora Police detectives accuse their former colleague of attempting to help cover up the pipe bomb detonations which were allegedly committed in December 2020 and January 2021 by a close friend of Christensen’s, Scott Alan Campbell. Detectives accuse Christensen of lying to police investigators and getting rid of his SUV, which was allegedly used by Campbell in one of the pipe bomb explosions.

According to the arrest affidavit for Christensen, “Curtiss Christensen knew Scott Campbell was responsible for the bombings and had advised Scott Campbell to get rid of the evidence before the ATF got involved.”

The case began when pipe bombs were detonated in Aurora on Dec. 25, 2020 and Jan. 7, 2021 in densely populated neighborhoods. In the December case, police say a security camera caught a dark colored SUV with a driver dropping what appeared to be a device with a lit fuse out the window. In the second case, a driver again dropped a pipe bomb from a moving car.

Both pipe bomb explosions were powerful and investigators wrote that “the likelihood of someone being injured or killed during the detonation of one of these explosive devices was very high. It is logical to assume that the suspect(s) either intended to injure or kill a resident or was indifferent regarding the potential injury or death of people in the area.”

Although Aurora police have not discussed the pipe bomb cases in detail, and sealed documents in Campbell’s criminal case, the newly obtained affidavit explains detectives obtained DNA from both pipe bombs which was then linked to Scott Alan Campbell, who had a previous criminal record, and his DNA was already on file.

They say Campbell “confessed to building and detonating the pipe bombs” and Campbell “wrote an apology letter to the victims of these events, further confessing his involvement.”

As police continued to investigate the case, they learned Campbell lived with Christensen, and dated Christensen’s daughter.

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Scott Alan Campbell (credit: Aurora)

Investigators say after the Christmas Day pipe bomb explosion, Campbell texted Christensen seeking help concealing the crime. They say Christensen offered advice on how to cover it up.

“Christensen was aware that a crime had been committed involving the Nissan Pathfinder (registered to him) and the trailer Campbell pulled with the Pathfinder.” They say Christensen offered tips on how to prevent police from finding the SUV.

Detectives say when they interviewed the former police sergeant, he lied to them repeatedly about what he knew.

Additionally, they say Christensen told Campbell to “get rid of everything” before the ATF got involved in the case. According to the affidavit, “Curtiss Christensen is a retired police sergeant and would know, through that experience, that the ATF is primarily responsible for investigating explosives and firearms charges.”

The APD investigators wrote Christensen was “advising Scott Campbell to destroy evidence of his involvement in the pipe bomb detonations before the ATF figured out Scott Campbell was involved.”

Police say six days after the December pipe bombing, after he learned Campbell had allegedly used his SUV in the Christmas bombing, Christensen donated his SUV -suspected of being used in the crime- to a Denver charity.

Investigators theorized Christensen was low on money, and “it would be unlikely that Curtiss Christensen would simply donate a vehicle that could otherwise be sold for some amount of money. Furthermore,” reads the affidavit, “the evidence indicates that Curtiss Christensen concealed physical evidence in this case (the 2004 Nissan Pathfinder) by donating it to Step Denver to prevent investigators from locating the vehicle.”

After being arrested last week for accessory after the fact to first degree arson, tampering with physical evidence and unlawful purchase of firearms, Christensen posted $75,000 bond and was released from jail.

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Campbell remains jailed on numerous charges including attempted murder and arson.

Brian Maass