Grand and Petty Theft
The legislature has established two classifications of theft. The difference between these two crimes is the value of the loss suffered by the person who is the victim. The loss can either be cash, real or personal property, or services rendered. If any of these are taken or fraudulently acquired, a theft occurs. A grand theft generally results if the value of the property, services, or currency taken exceeds $950.
Petty theft includes thefts that are not grand theft where the value of the property taken is less than $950. In most cases, it is a misdemeanor.
In cases where the value of the property or labor in less than $50 the offense can be charge as either an infraction (no jail time can be imposed) with a fine not to exceed $250, or a misdemeanor.
There are exceptions to this general rule. When a thief has a prior conviction for committing a serious or violent crime,  or a prior offense requiring registration as a sex offender,  a theft which is normally only a petty theft can be charged as a felony.  However this exception does not apply to those offenses that qualify only as infractions.VALUE OF PROPERTY TAKEN
“Reasonable and Fair Market Value” of property taken is generally the basis for determining its value for purposes of of classifying it as either a petty or grand theft.
Important factors to consider when determining reasonable value is the value of the property when it was stolen, and its value at the location of the theft.PROOF OF VALUE.
Either opinion evidence offered by experts or in some cases circumstantial evidence that supports value, can be used to determine the value of stolen property. The owner’s claim as to the value may provide evidence of its value, however the unique value to the owner is generally not relevant.
Where “personal services” were provided in producing the property, or increasing its value, the value of those become an element of the total value. Where there is a contract which specifies the value of those services, then it can be used to determine that value. Where no contract is available then the reasonable and going wage at the time for the services performed is added to reach the cumulative value of the property.SHOPLIFTING
A fact many people are unaware of is when a person enters a business with the intent to commit a theft or shoplift of property valued at $950 or greater, that entry is considered a commercial burglary and is separate and apart from the actual theft.
 Section 486 of the California Penal Code http://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=PEN§ionNum=486.
 Section 487 (a) of the California Penal Code http://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?sectionNum=487.&lawCode=PEN
 Section 488 of the California Penal Code. http://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?sectionNum=487.&lawCode=PEN
 Section 490.1 of the California Penal Code. http://law.justia.com/codes/california/2013/code-pen/part-1/title-13/chapter-5/section-490.1
 Section 667(e)(2)(C)(iv) of the California Penal Code. http://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=PEN§ionNum=667
 Section 290(c) 666 of the California Penal Code. http://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=PEN§ionNum=1170.18.
 Section 490.2(b) of the California Penal Code. http://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?sectionNum=490.2.&lawCode=PEN
 Sections 678, 484(a) of the California Penal Code. https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?sectionNum=484.&lawCode=PEN http://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?sectionNum=678.&lawCode=PEN
 People v. Quiel (1945) 68 C.A.2d 678 http://law.justia.com/cases/california/court-of-appeal/2d/68/674.html; People v. Leyvas (1946) 73 C.A.2d 863, 866 http://caselaw.findlaw.com/ca-court-of-appeal/1793184.html; People v. Franco (1970) 4 C.A.3d 535, 542. http://law.justia.com/cases/california/court-of-appeal/3d/4/535.html
 People v. Love (2008) 166 C.A.4th 1292, 1301. http://caselaw.findlaw.com/summary/opinion/ca-court-of-appeal/2008/09/16/159985.html
 Hambarian v. Superior Court (2002) 27 C.4th 826, 840. http://law.justia.com/cases/california/supreme-court/4th/27/826.html
 Section 484 (a) of the California Penal Code. https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?sectionNum=484.&lawCode=PEN
 Section 459.5(a) of the California Penal Code http://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=PEN§ionNum=459.5.