(CNN) Jurors will be allowed to consider the so-called castle doctrine in the murder case against former Dallas police officer Amber Guyger, who said she mistakenly entered the wrong apartment and killed a 26-year-old man.

The castle doctrine is the legal notion that your home is your castle, and you have the right to use lethal force to defend your home and not retreat. A number of states have enshrined the castle doctrine in statutory law, sometimes with slightly different guidelines for when deadly force can be used. In other states, stand your ground measures extend self-defense protections to any place a person has a legal right to be, including their home.

Guyger, 31, was indicted on a murder charge after she killed Botham Jean, an accountant, in September 2018. Jurors, who began deliberating on Monday, were instructed to find whether Guyger is guilty of murder, manslaughter or neither.

Prosecutors objected to applying the castle doctrine because Guyger was in Jean's home -- not the other way around. But the judge allowed it and the defense leaned on it.

Guyger's defense attorneys argue it is reasonable that she thought she was in her home and that it's a mistake any ordinary person would make in such a situation.

Therefore, it's reasonable that she acted in self-defense, her attorneys argue.

Guyger testified she entered Jean's apartment thinking it was hers, and believed she encountered a burglar who might kill her. Jean's apartment was one floor above Guyger's.

"The law recognizes that mistakes can be made. It's always tragic. The law's not perfect. It's tragic, but you have to follow this law," Attorney Toby Shook said during closing statements on Monday.

Amber Guyger and Botham Jean

Shook said when self-defense is raised, prosecutors "must prove beyond a reasonable doubt the defendant wasn't acting in self-defense ... And if they can't do that, it's not guilty."

"Who would not have sympathy for Botham Jean? Wonderful human being -- died in these horrible, tragic circumstances," Shook said. "Who would not have sympathy for his family or anyone in that position? Everyone does, but that is not part of your consideration as a jury."

Prosecutors argue that Guyger saw several numerous signs indicating she was on wrong floor and at the wrong apartment, including a skylight, a neighbor's decorative planter, Jean's red doormat and differences in the hallways.

"So, her eyes aren't working, her ears aren't working, her sense of touch isn't working, her sense of smell isn't working? I mean, my God. This is crazy," prosecutor Jason Fine, said Monday. "It was unreasonable. She should have known she was...in the wrong apartment."

Lead prosecutor Jason Hermus argued that self-defense claims must pass a multi-prong test, and Guyger failed to meet two of the standards: that her use of deadly force was "immediately necessary" and she had no other alternative, and needed to employ deadly force for protection.

Guyger was safe in the hallway, behind a door when she first suspected an intruder was in her home, Hermus said. She had a police radio and a phone to call authorities. She could've taken cover behind a nearby set of fire doors or retreated down the hallway, Hermus said.

Fine said if an intruder barged in on Jean, he "has a right to shoot that person under castle doctrine, not the other way around."

"It protects homeowners against intruders and now all of a sudden, the intruder is trying to use it against the homeowner," Fine said. "This law is not in place for her, it's in place for Bo."

CNN legal analyst Paul Callan said he believes it's a stretch for District Judge Tammy Kemp to give Guyger the benefit of the doubt under the castle doctrine as a possible defense.

"The castle doctrine might give the jury an excuse to acquit officer Guyger even though she was not in her own home when she shot and killed Botham Jean," Callan, a former homicide prosecutor, said in an email to CNN Monday night.

Dallas police fired Guyger after the shooting.