Habitual offender laws are written such that they represent distinct crimes. In your given example, the trier of fact will be asked to judge two distinct crimes:
- Did the defendant rob the bank
- Did the defendant break the habitual offender act
An example from California, Penal Code Section 193.7 defines habitual offenders for traffic offenses:
A person convicted of a violation of subdivision (b) of Section 191.5 that occurred within seven years of two or more separate violations of Section 23103, as specified in Section 23103.5, of, or Section 23152 or 23153 of, the Vehicle Code, or any combination thereof, that resulted in convictions, shall be designated as an habitual traffic offender subject to paragraph (3) of subdivision (e) of Section 14601.3 of the Vehicle Code, for a period of three years, subsequent to the conviction. The person shall be advised of this designation pursuant to subdivision (b) of Section 13350 of the Vehicle Code.
The conviction of being an habitual traffic offender is applied an underlying statute's sentencing guidelines. In the case of California's Vehicle Code 14601.3(e)(3):
Any habitual traffic offender designated under Section 193.7 of the Penal Code or under subdivision (b) of Section 23546, subdivision (b) of Section 23550, subdivision (b) of Section 23550.5, or subdivision (d) of Section 23566 who is convicted of a violation of Section 14601.2 shall be punished by imprisonment in the county jail for 180 days and by a fine of two thousand dollars ($2,000). The penalty in this paragraph shall be consecutive to that imposed for the violation of any other law.
In this case, there is enhanced sentencing if one is convicted of the crime of driving under a suspended or revoked license if the person is also convicted of being an habitual traffic offender.
The jury instruction template used when determining if an enhanced sentence is warranted requires that the defendant be found guilty of the underlying crime as well as the additional allegation of the sentencing factor:
If you find the defendant guilty of the crime[s] charged in Count[s]
_________________[,] [or of attempting to commit (that/those) crime[s]][ or thelesser crimes[s] of ], you must then decide whether[, for each crime,] the People have proved the additional allegation that <insert description of enhancement, sentencing factor, or factual issue>. [You must decide whether the People have proved this allegation for each crime and return a separate finding for each crime.
To prove this allegation, the People must prove that:
<Insert elements required.>
The People have the burden of proving each allegation beyond a reasonable doubt. If the People have not met this burden, you must find that the allegation has not been proved.
The person in your example is not being punished again for the first crime; they are being sentenced to a year for robbing the bank the second time and receiving a sentencing enhancement of a year for breaking the habitual offender statute.