Attacking Colorado Mandatory Arrests For Domestic Violence: The Motion to Suppress

Prosecutors will typically argue that the totality of the known facts established probable cause and that, even if the arrest was unlawful, the challenged evidence is not a suppressible fruit of the arrest.

The strongest response depends on identifying the precise evidence, when it was acquired, and the officers’ actual pre-arrest knowledge.

A Chart On The Principal Prosecution Arguments

Prosecution argument	Authority	Defense focus
Probable cause existed under the totality. Officers may draw reasonable inferences from circumstantial facts; innocent explanations do not negate probable cause.	People v. Castaneda, 249 P.3d 1119, 1121–23 (Colo. 2011).	Segregate facts known before arrest; identify unsupported assumptions, material contradictions, and facts ignored by the officer.
Mandatory arrest applied. Once probable cause supported an underlying domestic-violence offense, the officer had a statutory duty to arrest.	Colo. Rev. Stat. § 18-6-803.6(1) (2026).	The statute requires—it does not replace—probable cause for a crime involving domestic violence. Challenge both the predicate offense and the DV nexus.
The complainant’s account and corroboration were enough.	People v. Castaneda, 249 P.3d 1119, 1121–23 (Colo. 2011).	Establish that the account was internally inconsistent, objectively implausible, or contradicted by footage, injuries, physical evidence, 911 audio, or neutral witnesses.
Self-defense was considered but did not eliminate probable cause. The statute requires consideration, not acceptance, of competing accounts.	Colo. Rev. Stat. § 18-6-803.6(2)(a)–(d) (2026).	Show the officer did not separately evaluate cross-complaints or failed to consider comparative injuries, future risk, prior complaints, or self-defense evidence.
Collective knowledge supplied the basis for arrest.	People v. Arias, 159 P.3d 134, 140–41 (Colo. 2007).	Require proof that the arresting officer acted on a communication or direction from an officer who already possessed sufficient reasonable suspicion or probable cause. Information deliberately withheld from the arresting officer cannot later be imputed.
A good-faith mistake or technical violation bars suppression.	Colo. Rev. Stat. § 16-3-308(1)–(2) (2026).	Argue that this was not a “reasonable judgmental error” about facts or law that, if true, would establish probable cause, but a failure to obtain sufficient facts, disregard of material exculpatory evidence, or an unreasonable legal conclusion.
The challenged evidence was not fruit of the arrest.	Brown v. Illinois, 422 U.S. 590, 599, 603–04 (1975).	Establish causation and exploitation: identify how arrest, custody, interrogation, or a search incident to arrest produced the evidence.

Exceptions and Remedy-Based Arguments

1. Attenuation

The prosecution may contend that an intervening event dissipated the taint—for example, a meaningful break in time, release and voluntary return, an independent decision to speak, or another intervening legal event. Miranda warnings alone do not automatically attenuate an unlawful arrest. Brown v. Illinois, 422 U.S. 590, 602–04 (1975).

The critical question is whether police obtained the evidence by exploiting the illegality or instead by a means sufficiently distinguishable to purge the taint. Brown v. Illinois, 422 U.S. 590, 599 (1975).

Defense response: An experienced criminal defense lawyer will emphasize temporal proximity, continuous custody, the absence of meaningful intervening events, the purposefulness of police conduct, and the direct relationship between the arrest and the statement or search.

2. Voluntary Statements and Miranda Waiver

The People may also argue that the defendant was properly advised, waived Miranda rights voluntarily, and then made an admissible statement. But a valid Miranda waiver addresses Fifth Amendment compulsion; it does not, by itself, cure a Fourth Amendment arrest unsupported by probable cause. Brown v. Illinois, 422 U.S. 590, 601–04 (1975).

Colorado’s statutory rule separately provides that otherwise admissible evidence obtained through a voluntary noncustodial confession may not be suppressed. Colo. Rev. Stat. § 16-3-308(3) (2026).

Defense response: An experienced criminal defense lawyer will demonstrate custody, the arrest’s direct causal effect, lack of attenuation, or involuntariness.

3. New York v. Harris / Station House Statements

Where police had probable cause to arrest but made an unlawful warrantless entry into the defendant’s home, the prosecution may rely on New York v. Harris, 495 U.S. 14, 18–21 (1990) and People v. Davis, 187 P.3d 562, 565–67 (Colo. 2008) to argue that Mirandized station house statements remain admissible. Colorado’s Supreme Court held that Harris applies when police had probable cause and the claimed illegality was the warrantless in-home arrest.

Critical limitation: Harris and Davis do not validate statements where the central defect is the lack of probable cause itself. Their rationale rests expressly on the premise that probable cause existed.

4. Independent Source or Inevitable Discovery

The prosecution may also argue that officers acquired the evidence independently of the arrest or would have lawfully discovered it anyway.

Defense response: An experienced criminal defense lawyer will require concrete, non-speculative proof of a genuinely independent lawful source or established lawful process that would have produced the same evidence. A post hoc assertion that police “could have” sought a warrant is ordinarily insufficient without proof of an actual, independent evidentiary path.

5. The Good-Faith Statutory Exception

The People may invoke Colo. Rev. Stat. § 16-3-308 (2026), which forbids suppression of otherwise admissible evidence obtained from a peace officer’s “good faith mistake” or “technical violation.”  A good-faith mistake is a reasonable judgmental error concerning facts or law that, if true, would establish probable cause. Colo. Rev. Stat. § 16-3-308(2)(a) (2026).

The statute also declares prima facie good faith when evidence is obtained pursuant to a warrant and within its scope, absent an intentional and material misrepresentation. Colo. Rev. Stat. § 16-3-308(4)(b) (2026).

Defense response:

• • No objectively reasonable factual or legal mistake;
  • Omitted or disregarded exculpatory information;
  • No warrant, or execution outside a warrant’s scope;
  • Intentional or material misrepresentation in the warrant process; or
  • As constitutional violation for which statutory good faith cannot displace the governing constitutional remedy.

6. Lack of Causal Connection

Even if the arrest lacked probable cause, the prosecution may argue that a particular item is not suppressible because it was obtained before the arrest or acquired independently. For example, a complainant’s statements, observations made from a lawful location, and evidence possessed before the arrest are not fruits of the arrest merely because the police later arrested the defendant unlawfully.

Defense response: An experienced criminal defense lawyer will itemize in their motion the obvious requested remedy. For each statement, physical item, digital extraction, consent, or search, the prosecution must identify the specific arrest-related conduct that led to its acquisition.

Domestic-Violence-Specific Rebuttal

Finally, the prosecution may stress that Colorado law compels action once probable cause is found. Colo. Rev. Stat. § 18-6-803.6(1) (2026). But the statutory command is more individualized: officers must evaluate each complaint separately and consider injuries, prior complaints, future danger, and self-defense. Colo. Rev. Stat. § 18-6-803.6(2) (2026).

Accordingly, the defense should frame the suppression hearing around:

• The specific underlying offense;
• The evidence known before arrest;
• The uninvestigated or ignored exculpatory facts;
• The officer’s compliance with the cross-complaint/self-defense inquiry; and
• The direct causal path from arrest to each item sought to be suppressed.

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The Bottom Line

Colorado’s mandatory-arrest statute is not a presumption that the accused committed domestic violence. It requires an antecedent probable-cause determination that a particular crime or offense occurred and that it involved domestic violence as Colorado defines that term. Colo. Rev. Stat. § 18-6-803.6(1) (2025). A disciplined defense attacks both links: the factual basis for the underlying offense and the statutory basis for characterizing that offense as domestic violence.

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Colorado Criminal Law – Attacking Colorado Mandatory Arrests For Domestic Violence: The Motion to Suppress

The reader is alerted that Colorado criminal law, like criminal law in every state and at the Federal level, changes constantly. The article above was accurate when it was drafted, but it cannot account for changes that occurred after it was uploaded.

ABOUT THE AUTHOR: H. Michael Steinberg – Email the Author at: hmsteinberg@hotmail.com

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