It is illegal for anybody to bring certain forms of contraband into a jail or prison in Oklahoma.
57 O.S. §21 Provides that persons bringing guns, knives, bombs, or any dangerous instrument, any controlled dangerous substance, any intoxicating beverage or low-point beer, money or financial instruments for anyone other than the inmate or their spouse (including tax returns!) is guilty of a felony and subject to a penalty of from 1 to 5 years in prison.
It provides that an inmate in possession of the above items is subject to a term of 5 to 20 years in prison and that inmates with two or more prior felony convictions are subject to a term of 10 to 20 years in state prison.
Bringing tobacco into a penal facility or having it as an inmate is a misdemeanor and will get you up to a year in the county jail.
All of the above actions are also subject to substantial fines in addition to the time in custody.
Supposing that you have been charged under the authority of this statute, what's going to happen in your case?
There are four fact patterns that are prevalent regarding the application of this statute: the first one is being found in possession while an inmate. For example, an inmate is found with a knife or some heroin or whatever. Unless he can show he didn't actually or constructively possess the contraband he is likely to get some prison time tacked on to his current sentence. One way of showing a lack of such possession is to point out that more than one person occupies a cell or the contraband was hidden particularly well (behind a ceiling tile, for instance).
The second fact pattern is about a visitor trying to smuggle in contraband. Generally it's taped between their legs under their skirt (it's usually women) and they try to smuggle it out and over to an inmate by passing it under a table. Generally there is video of the incident and the person watching the video sees all the awkward maneuvering of the visitor. They then search the inmate after the visit and accuse the visitor of smuggling what they found.
The third fact pattern is about an employee of the facility bringing in contraband and distributing it to prisoners in exchange for cash (sometimes for sex). This one probably works pretty well since the employee has a better chance of understanding how people get caught smuggling in contraband. But, if you read the papers, plenty of people get caught doing this every year, like clockwork.
The fourth fact pattern is more interesting. A person is arrested for whatever reason. They are read their Miranda rights (and keep their mouth shut) and brought to the county or municipal jail by the police or sheriff. They are searched upon being booked into the jail and the jailor finds contraband. The contraband is reported to the District Attorney who promptly files a felony charge of bringing contraband into a penal facility.
The problem here, for the State, is that they have to prove willfulness. If the defendant didn't voluntarily go to the jail, then when did he willfully carry contraband into it? In discussing this issue with prosecutors they tend to indicate that the defendant should have disclosed the presence of the contraband prior to being taken to the jail. However the defendant has a Constitutional right to refrain from incriminating himself and he must be prepared to assert his right through counsel.
As general advice if you're being arrested and have something on your person thatt isn't contraband outside a penal facility then you should definitely disclose it (for instance, cigarettes or a pocket knife). You don't incriminate yourself by declaring that you possess an item that is not ordinarily contraband. This is probably the only time I would ever advocate talking to the cops without a lawyer present.