LAS VEGAS (KLAS) — The inmate accused of killing another inmate inside the Clark County Detention Center has a lengthy criminal record and told investigators he killed his cellmate because the man was “running his mouth,” documents the 8 News Now Investigators obtained Wednesday said.

The homicide occurred inside one of the jail’s psychiatric units on Tuesday afternoon.

Lee Johnson, 30, who was in jail on charges of battery on a protected person, is accused of killing James Chatien, who was in custody for showing his genitals to a group of children, documents said.

Lee Johnson, 30, who was in jail on charges of battery on a protected person, is accused of killing his cellmate in the Clark County Detention Center. (LVMPD/KLAS)

Chatien and Johnson were housed in a cell together, documents said. Officers noted Chatien had several prior incidents of misusing a cell call light to alert officers.

At 1:47 p.m., the cell light was activated. A corrections officer deactivated the light two minutes later. The light was reactivated at 1:53 p.m.

At 2:04 p.m., a corrections officer spoke to Johnson at the cell’s door. The officer could not see Chatien in the cell and called for help. Chatien was then discovered unresponsive in the cell with blood around his head, documents said. Investigators suspect Johnson beat Chatien to death.

While speaking to investigators, Johnson said “the incident happened because his roommate was running his mouth after he cleaned the cell.”

Records show James Chatien was murdered inside the Clark County Detention Center on Tuesday, Oct. 18, 2022. (LVMPD/KLAS)

“He said he was tired of being disrespected, so ‘I tried to kill him, you got a problem with that?'” officers wrote in documents the 8 News Now Investigators obtained.

Johnson faces new charges of open murder and battery by a prisoner.

On Oct. 7, police stopped Johnson as he was attempting to the street near Maryland Parkway and Desert Inn Road for failing to obey the walk signal, records showed. Johnson then began fighting with several officers, a report said.

“[Johnson] was told to give up and let us place him [in] custody,” police wrote. “[Johnson] started moving around attempting to break free [from the officer’s grip] and began saying, ‘I’ll kill you.”

Johnson then fought with another officer before being placed in a cruiser and banging his weapon on the window, police said.

In 2017, Johnson was accused of beating another inmate inside the jail’s booking area, records showed. His record includes several prior felonies and misdemeanors.

Chatien was in and out of jail for competency determinations. A judge most recently ordered him not competent in September. He had a hearing scheduled for Friday.