Sentence of 15-25 years. Who finally decides the duration?

[surprise_i'm_armed]

This question might be directed to Charles Cotton, srothstein, or gigag04:

When a perp is found guilty of something and sentenced to a sentence of
"15-25 years", when is the final determination made of how long the perp
will be a guest of the Graybar Hotel?

Does the Texas Department of Corrections determine the actual length
of incarceration based on good behavior?

Does the Parole Board decide this based on ongoing interviews with the
perp?

Does the perp's lawyer have to keep introducing motions for his release?

Just how does this indeterminate sentencing work?

Thanks in advance.

SIA

[RPB]

I'll add a little to the question if it's ok.

I was a juror in Ted Poe's Court where we found a negligent homicide drunk driver, intoxication assault ... etc guilty, and he added to the sentence...

After we gave our punishment, He found the car to be a deadly weapon, increasing the punishment because it was a deadly weapon, then, he ALSO added to the fine we assessed, an additional amount for restitution to be paid prior to release, out of money the convicted person earned in prison at so many dollars per day.

So, the guy we sentenced to ten years, may or may not be out in ten, or 15 etc ...?

Not sure what me question is other than I'm not sure I understood how he did that when we thought we already assessed a sentence/punishment in the jury room, not saying it was good or bad, just surprised me that he added to it (very different at the civil and Family court buildings lol).

And same as above questions
Just how does this indeterminate sentencing work?

[MoJo]

The convict decides how long the sentence will be by their behavior. Good con = short time in slammer bad con = long time. My wife's brother's ex-wife is an example of the bad con; she has been up for parole several times. Due to disciplinary issues, it looks like she will take the full 20 year ride.

[Texas Dan Mosby]

Taken from a similar thread on another forum:

After conviction in court, further information can be gathered and used to determine sentencing, depending on the jurisdiction and crime, etc...

In the federal system, they have to send it to probation who investigates the person, the results of the crime, and how it hurt the victims. They write a report and give it to the judge so he knows really who the guy/gal is, and everything about their life from how much they have in the bank, to performance appraisals at work, and how the victim really feels. The judge can use all that as he/she decides what punishment is appropriate.

On a homicide like the one you're asking about, the judge orders a presentence investigation with a subsequent report. That includes things that aren't in the original investigation due to admissibility issues. The defendant's background, victim's background, victim (family) impact statements, mitigating and aggravating factors, etc.

As stated before, the convicts' behavior in prison can also influence the total time spent behind bars.