In Colorado, the law states on use of force in defense of property (source Legal Resources);

18-1-706. Use of physical force in defense of property.

A person is justified in using reasonable and appropriate physical force upon another person when and to the extent that he reasonably believes it necessary to prevent what he reasonably believes to be an attempt by the other person to commit theft, criminal mischief, or criminal tampering involving property, but he may use deadly physical force under these circumstances only in defense of himself or another as described in section 18-1-704.

ANNOTATION

One cannot instantly kill in defense of property. While a man may use all reasonable and necessary force to defend his real and personal estate, of which he is in the actual possession, against another who comes to dispossess him without right, he cannot instantly carry his defense to the extent of killing the aggressor. If no other way is open, he must yield and get himself righted by resort to the law. Bush v. People, 10 Colo. 566, 16 P. 290 (1887) (decided under G. S. § 721).
Now the above highlighted item is vague, and the situation may change depending on the BGs actions. Yet another I will need to verify.

However, under Use of force in defense of a person;

18-1-704. Use of physical force in defense of a person.

(2) Deadly physical force may be used only if a person reasonably believes a lesser degree of force is inadequate and:

(b) The other person is using or reasonably appears about to use physical force against an occupant of a dwelling or business establishment while committing or attempting to commit burglary as defined in sections 18-4-202 to 18-4-204; or

(c) The other person is committing or reasonably appears about to commit ... robbery as defined in section 18-4-301...

ANNOTATION

The defendant, if he did not provoke the assault, is not obliged to retreat or flee to save his life, but may stand his ground, and even, in some circumstances, pursue his assailant until the latter has been disarmed or disabled from carrying into effect his unlawful purpose, and this right of the defendant goes even to the extent, if necessary, of taking human life. Boykin v. People, 22 Colo. 496, 45 P. 419 (1896); Enyart v. People, 67 Colo. 434, 180 P. 722 (1919).

Right to kill in self-defense is not limited to cases where assailant intends to commit a felony. Ritchey v. People, 23 Colo. 314, 47 P. 272 (1896).

Instruction on use of deadly physical force is to be used only if the victim died. Because no victim died, instruction that defendant was justified in use of physical force if he used that degree of force which he reasonably believed to be necessary was proper. People v. Silva, 987 P.2d 909 (Colo. App. 1999).


18-4-202. First degree burglary.

(1) A person commits first degree burglary if the person knowingly enters unlawfully, or remains unlawfully after a lawful or unlawful entry, in a building or occupied structure with intent to commit therein a crime, other than trespass as defined in this article, against another person or property, and if in effecting entry or while in the building or occupied structure or in immediate flight therefrom, the person or another participant in the crime assaults or menaces any person, or the person or another participant is armed with explosives or a deadly weapon.

(2) First degree burglary is a class 3 felony.

ANNOTATION

Distinguished from felony menacing. It is possible to commit a first degree burglary without also perpetrating felony menacing. The merger doctrine does not apply because there is no requirement in this section that a victim be placed in fear of imminent serious bodily injury by a deadly weapon as there is in the felony menacing statute. People v. Sisneros, 44 Colo. App. 65, 606 P.2d 1317 (1980).

There is no requirement that victim be placed in fear of imminent serious bodily injury by a deadly weapon under the first degree burglary statute. People v. Montanez, 944 P.2d 529 (Colo. App. 1996).

Where the only evidence concerning the presence of deadly weapons at the time of the robbery was that defendant was carrying stolen items, including weapons, in a canvas sack during commission of the burglary, such evidence was insufficient to prove that defendant was armed with a deadly weapon, a requisite element of burglary. People v. Moore, 841 P.2d 320 (Colo. App. 1992).

Second degree burglary becomes first degree burglary when the perpetrator increases the risk of deadly or bodily harm to an occupant or other person present by possessing a deadly weapon such that he knowingly places or attempts to place such person in fear of serious bodily injury or intends to and does cause serious bodily injury to any person. People v. Moore, 841 P.2d 320 (Colo. App. 1992).

If the defendant steals a deadly weapon and thereby becomes armed with a deadly weapon, the burglary is elevated to first degree, and there is no requirement that the prosecution show that the defendant assaulted or menaced anyone with the deadly weapon. People v. Loomis, 857 P.2d 478 (Colo. App. 1992).

The defendant is considered "armed" with a deadly weapon if the weapon is easily accessible and readily available for use by the defendant. The court need not consider the defendant's willingness or present ability to use the deadly weapon. People v. Loomis, 857 P.2d 478 (Colo. App. 1992).



18-4-204. Third degree burglary.

(1) A person commits third degree burglary if with intent to commit a crime he enters or breaks into any vault, safe, cash register, coin vending machine, product dispenser, money depository, safety deposit box, coin telephone, coin box, or other apparatus or equipment whether or not coin operated.

(2) Third degree burglary is a class 5 felony, but it is a class 4 felony if it is a burglary, the objective of which is the theft of a controlled substance, as defined in section 12-22-303 (7), C.R.S., lawfully kept in or upon the property burglarized.


18-4-301. Robbery.

(1) A person who knowingly takes anything of value from the person or presence of another by the use of force, threats, or intimidation commits robbery.

(2) Robbery is a class 4 felony.

I have deleted easily 700 lines of content from the above copied/pasted laws after reading them. They did not apply to the discussion by my interpretation. INAL!!!