KANSAS CITY, Mo. — A Kansas City man charged in the shooting deaths of three people, including his 1-year-old son, has married the woman who told police she witnessed the killings, potentially putting the state’s case in jeopardy.

Jackson County prosecutors said in court documents that they believe the marriage was intended to prevent Shellana Victoria Davis from testifying against Joseph L. Nelson under the state’s spousal privilege law. Nelson, 23, is charged with killing his ex-girlfriend, 17-year-old Bianca Fletcher, her boyfriend, and her and Nelson’s son on Sept. 8.

According to prosecutors, Davis told police she saw Nelson shoot Fletcher during an argument. They allege that he then shot Fletcher’s boyfriend, 18-year-old Shannon Rollins, to eliminate him as a witness and killed his and Fletcher’s son because he was afraid the baby’s cries would attract attention, The Kansas City Star reported.

Nelson has denied any involvement in the case.

He married Davis Dec. 7 while he was jailed on $1 million cash bond facing three charges of first-degree murder. Prosecutors sought a court order to formally interview Davis on tape before the couple was married, but the marriage occurred before the court ruled on the motion.

In the filing before the wedding, prosecutors said Davis’ detailed eyewitness account of the events formed “the basis for the felony charges filed in this matter.” Another court filing said the state is not aware of any other witnesses to the shootings, making Davis “an essential” witness for the state.

“It is alleged that (her) actions were intentional efforts to hinder the prosecution of a triple homicide,” prosecutors wrote of Davis’ plan to marry Nelson.

Davis, 20, was arrested the day of the wedding and charged with one count of first-degree burglary and two counts of tampering with evidence. She is jailed on $75,000 bond. A bond reduction hearing is scheduled for Jan. 27.

Frank O. Bowman III, a law professor at the University of Missouri, said state law appears to allow Davis to decline to testify against Nelson and would likely rule out admission of Davis’ statements to police because they would be considered hearsay and would violate the constitutional right for Nelson to confront his accuser.

“The privilege covers essentially the active testimony about anything, whether it occurred before, during or after the marriage,” Bowman said.

However, an exception in Missouri’s spousal privilege law says it does not apply if the murder victim is younger than 18. Two of the people killed Sept. 8 were under 18.

“If you have three homicides to be tried in unison, I’m not exactly sure how you split (them up). I guess the question arises, in order to get that testimony, what does the prosecution have to do?” Bowman said.