Although legislative silence regarding mental state is not conclusive, "it is well settled that the legislature may make a prohibited act a crime, irrespective of the elements of intent or scienter, when public policy so requires." People v. Caddy, 189 Colo. 353, 354-55, 540 P.2d 1089, 1090 (1975). Section 18-1-502, C.R.S. (2006), sets forth the general requirements for criminal liability:

Examples of strict liability public welfare offenses are speeding and driving under the influence. People v. Caddy, 189 Colo. 353, 354-55; 540 P.2d 1089, 1091 (1975) (speeding); People v. Senn, 824 P.2d 822, 824 n. 3 (Colo. 1992) (driving under the influence). Several other states have held driving under restraint to be a constitutionally permissible strict liability crime.

In many states, speeding is a strict liability offense. See, e.g. , State v. Brown , 107 Wis.2d 44, 318 N.W.2d 370 (1982) ; People v. Caddy , 189 Colo. 353, 540 P.2d 1089 (1975). When caught speeding, drivers often blame unintended acceleration caused by their cruise control devices, suggesting that the law should not hold them responsible for a design flaw by the car manufacturer.

And in People v. Caddy , we noted that it was "well settled that the legislature may make a prohibited act a crime, irrespective of the elements of intent or scienter, when public policy so requires." 189 Colo. 353, 540 P.2d 1089, 1090 (1975) (emphasis added).See § 18-1-502 (providing that when a culpable mental state or mens rea is not required for the commission of an offense, "the offense is one of ‘strict liability’ ")

With the State having the burden of proving knowledge beyond a reasonable doubt, the prosecutor muddied the issue by equating a traffic offense with the charges against Toben. Speeding is a strict liability offense requiring no particular knowledge. State v. Caddy, 189 Colo. 353, 540 P.2d 1089 (1975) (mistake due to defective speedometer no defense). But as LaFave explains, “ignorance or mistake of fact or law is a defense when it negatives the existence of a mental state essential to the crime charged.”

Speeding is a strict liability offense, and the elements that must be established are that (1) the defendant was operating a motor vehicle (2) in excess of the applicable speed limit. See People v. Caddy, 189 Colo. 353, 540 P.2d 1089 (1975). C.

1981); see generally People v. Rostad, 669 P.2d 126 (Colo. 1983) In such cases, "the burden is placed upon the actor of ascertaining at his peril whether his deed is within the prohibition of any criminal statute." People v. Caddy, 189 Colo. 353, 355, 540 P.2d 1089, 1091 (1975). Those strict liability statutes which potentially abut upon constitutional freedoms must be narrowly drawn to avoid vagueness and overbreadth problems.

However, crimes which have their origin in common law must contain a mens rea element. Morissette v. United States, 342 U.S. 246, 72 S.Ct. 240, 96 L.Ed. 288 (1952); People v. Washburn, 197 Colo. 419, 539 P.2d 962 (1979); People v. Caddy, 189 Colo. 353, 540 P.2d 1089 (1975). Second-degree criminal trespass is a crime which has its origin in common law.

Thus, we first address the issue of the culpable mental state required in section 18-4-402(1)(b), C.R.S. 1973, both before and after amendment. [1,2] The legislature can proscribe an act without regard to a culpable mental state, but only if it does so pursuant to its police power. Morissette, supra; People v. Caddy, 189 Colo. 353, 540 P.2d 1089 (1975). Such is not the statute in this case.

SeePeople v. Ellison , 14 P.3d 1034, 1038 (Colo. 2000). Maloy is correct that strict liability crimes tend to be public welfare offenses — like speeding, seePeople v. Caddy , 189 Colo. 353, 355, 540 P.2d 1089, 1091 (1975), or public indecency, seePeople v. Hoskay , 87 P.3d 194, 198 (Colo. App. 2003) — and often carry lower penalties than other crimes. But he's not correct that the child prostitution statutes are strict liability crimes merely because defendants can't present an affirmative defense to the age element.