The Massachusetts witness intimidation statute (chapter 268, section 13B) prohibits any person from misleading a police officer with the intent to impede a criminal investigation.
In Commonwealth v. Steven Morse (SJC-11433, decided June 13, 2014), the defendant was operating a boat that struck and killed a child. During the ensuing investigation, the police asked him if he had consumed any substances that could have impaired his ability to be aware of what was going on around him. The defendant answered no, even though he had recently smoked marijuana, and he was convicted at trial under the witness intimidation statute.
The Supreme Judicial Court reversed, ruling that even if a defendant makes an objectively misleading statement to the police, the prosecutor must prove that the defendant specifically intended to “impede, obstruct, delay, harm, punish, or otherwise interfere” with a criminal investigation. The Court wrote, “absent additional evidence of specific intent, such exculpatory denials, standing alone, rarely will permit a reasonable inference that the defendant possessed the specific intent necessary to establish a violation of section 13B.”
Of course, this problem can be avoided altogether by never speaking to the police without consulting a criminal defense attorney beforehand.