A Missouri woman accused of dealing drugs from a home where an ex-convict fatally shot one police officer and wounded two others is now charged with first-degree murder and, if convicted, she could be sentenced to death or a life in prison.

Prosecutors announced Wednesday that the charge against 37-year-old Tammy Dee Widger has been upgraded from second-degree murder in the death of Officer Ryan Morton. The Kansas City Star reported that she also faces two first-degree assault charges and felony drug counts.

Officers mistakenly went to Widger's home in Clinton last month in response to a 911 call, instead of a property in town 20 miles (32 kilometers) away. Widger said in a jailhouse interview that she thought James Waters had slipped out the back to avoid police when she let the officers inside, and that she didn't know he had a gun. Waters opened fire before barricading himself inside the home.

Waters and Morton were found dead inside the home hours later.

The Henry County Prosecutor's Office said that although Waters is believed to have shot the officers, Widger can be charged with the same offense he would have faced if it's shown that she aided in the offense, either before or during the crime.

Updated charging documents filed by investigators say Waters sent text messages asking Widger to "go home and load both of the 410's now." Police do not say when the text was sent. Shotguns using the .410 caliber were found in the residence after the shooting.

A witness stated that Waters often carried a weapon and commonly said if anything ever happened to him, "he was going to go out shooting," including in front of Widger.

Police also write that although Widger insisted Waters had left the residence before the shooting, a review of surveillance footage from a camera installed there showed he had not.

Police also wrote that Widger "denied there were any weapons in the residence," although a pistol was found in her purse. Another witness told police of seeing "all kinds" of guns there.

Widger's attorney, Clifford Cohen, said he wouldn't comment before her preliminary hearing next month.