And if you prevent them from executing the warrant you can be held for...….
harboring a fugitive
Which by definitions is:
Harboring a fugitive refers to the crime of knowingly hiding a wanted criminal from the authorities. Federal and state laws, which vary by state, govern the crime of harboring a fugitive. Although supplying funds may make one an accessory after the fact, supplying financial assistance to a fugitive does not rise to the level of harboring or concealing. The federal statute, 18 U.S.C. § 1071, requires proof of four elements: (1) proof that a federal warrant had been issued for the fugitive' s arrest, (2) that the accused had knowledge that a warrant had been issued, (3) that the accused actually harbored or concealed the fugitive, and (4) that the accused intended to prevent the fugitive' s discovery or arrest.
In other words -
Obstructing the law enforcement officials from doing their job.