UPDATE 2:48 p.m.: Before his death, Shannon Lamb admitted to killing his girlfriend, Amy Prentiss, 41, in the home they shared in Mississippi, where authorities found a note saying "I am so sorry," according to the Associated Press.

Gautier police report coming across the note which read: "I am so sorry I wish I could take it back. I loved Amy and she is the only person who ever loved me."

Lamb did not reveal a motive for killing Prentiss, nor did he indicate that he had wanted to hurt anyone else when he gave his confession, but he still wound up killing Ethan Schmidt later. The motive for that death is still unknown as well. 

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Delta State University professor Shannon Lamb, domestic partner and the prime suspect in the shooting death of Ethan Schmidt, has died of a self-inflicted gunshot wound, according to The Washington Post.

The police had tried to stop Lamb late Monday in Cleveland, Miss. He was last seen driving a black 2011 Dodge Avenger that had Mississippi license plates on them.

Police officers followed Lamb, saw him pull his car over near Greenville and leave the car. He then proceeded to the woods, where the officers then heard a single gunshot.

The officers discovered Lamb's body and took him to a hospital where he died, Police Chief Charles Bingham said, according to the Clarion Ledger.

Delta State University was on lockdown Monday morning after an active shooter had emerged on campus at around 10:40 a.m., as previously reported by HNGN.

Faculty, staff and students were escorted out of the academic buildings and were transferred to Sillers Coliseum, where they remained during the duration of the campus lockdown until police authorities were able to escort them out of the area.

Lamb was initially identified as a person of interest but was upgraded to a suspect in the shooting later on, HNGN previously reported.

With reporting by Jelani James