JONESBOROUGH, Tenn. (WJHL) — A man accused of the fatal Johnson City shooting of 20-year-old Brionah Tester in March now faces an attempted murder charge following an alleged altercation in the Washington County Detention Center.

An affidavit from the Washington County, Tennessee Sheriff’s Office (WCSO) states that Billy Joe Anderson, 34, stabbed another inmate with “some type of sharp glass material” after entering the victim’s cell following recreation time.

WCSO investigators interviewed multiple witnesses and the victim, with witnesses saying Anderson hid in a shower area outside of his cell after recreation time ended. The affidavit says witnesses told officers Anderson and the victim had an altercation “on the date prior to this incident.”

Before refusing to answer questions without an attorney present, Anderson said “he wanted to be on ‘psyche (sic) meds’ and that he wanted to be housed alone so that ‘nothing else would happen,'” the affidavit states.

The attempted first-degree murder charge is based on the prior altercation and on Anderson’s allegedly lying in wait for the victim. A WCSO news release states the victim was reported to be in stable condition after being treated for his injuries at Johnson City Medical Center.

Anderson has been in jail for the March 18 murder of Brionah Tester, whose body was found in an apartment complex. He faces second-degree murder for Tester’s death and had reportedly been out on bond for several felony-level drug offenses when he is alleged to have killed her.

This weekend’s incident is the second alleged violent offense Anderson has committed since being jailed. He was charged with aggravated assault for an April 13 incident in which he allegedly assaulted a jail officer who was trying to free an inmate from a headlock Anderson had him in.

That jail officer testified that he saw a 5-inch metal “shank,” or homemade knife, in Anderson’s hand during the incident.

Saturday night’s altercation tacked another charge onto Anderson’s lengthy criminal record and added $100,000 to his bond for attempted first-degree murder.

He will appear in court Monday for the new charge, and the Criminal Investigations Division continues to investigate the incident.