Waseem Daker, defending himself against a murder charge, told a Cobb County jury on Thursday that he didn’t kill a Delta flight attendant or attack her 5-year-old son in 1995, and he doesn’t know who did.

Daker, 35, portrayed himself as an innocent target of a prosecutorial smear campaign. He said police only suspected him of killing Karmen Smith and stabbing her 5-year-old son Nick because Smith’s roommate, Loretta “Lottie” Spencer Blatz, who Daker has been convicted of stalking, indicated he could be responsible.

In an animated voice, Daker stood a few feet from jurors and said he set out to prove three things at trial: “Lottie and I had a relationship,” he said, holding up one finger.

“Lottie is a liar,” he added, holding up a second.

And third, Daker said, “I don’t think we’re going to establish who killed Karmen Smith, but evidence is going to show it wasn’t me.”

In previous testimony, Blatz insisted that she and Daker, who is nearly 12 years her junior, never had a romantic relationship and that they were merely friends who met while playing on a paintball tournament team. She said Daker became obsessed with her and began calling her, following her and breaking into her home.

He repeatedly threatened to kill himself if she wouldn’t talk to him, and as his obsession deepened he began to threaten harm to Blatz and her daughter as well, Blatz testified.

Assistant District Attorney Jesse Evans in his closing argument Thursday described Daker as a highly intelligent, cold-blooded killer who attacked Smith and her son on Oct. 23, 1995, perhaps because he wanted revenge against Blatz for complaining to police that he stalked her. The son survived.

Blatz’s complaints landed Daker in jail several times that year, yet Daker continued to call and harass Blatz even after a judge ordered him to have no contact her, court records show.

Daker was convicted of stalking Blatz in 1996, a year after Smith’s death. Authorities had long suspected that Daker killed Smith, but they were unable to link him until 2009, when DNA from hairs found on Smith’s body were tested and matched Daker.

Daker, 35, was indicted on 11 counts, including malice and felony murder, burglary, false imprisonment, aggravated assault, aggravated battery and attempted aggravated stalking. Jurors will begin deliberations Friday.

Evans hammered Daker with repeated references to the “proof positive” DNA evidence, when it was his turn to present a closing argument. He also read aloud from a torn-up letter Daker wrote during one of his stints in jail in 1995. Daker scribbled that he had a plan to get revenge on Blatz and was “plotting to destroy her, not kill her though.” Daker’s letter continued, “I will let her live.”

Daker has no formal legal education, except what he has learned from books while in jail. Dressed in a wrinkled beige suit and dark-colored tie, his wire-rimmed glasses resting high on his nose, Daker insisted that the state’s theory doesn’t make any sense. He questioned why, if he truly wanted revenge against Blatz, he wouldn’t have gone after her directly.

And as for the DNA evidence, Daker said he had been in Blatz’s car and in her apartment on numerous occasions when they dated, and theorized that his hairs may have been transferred to Smith when the two roommates interacted.

However, prosecutors were quick to point out that the telltale hairs were found underneath Smith’s shirt, and that her body was nestled under five layers of blankets that the killer had pulled up to her neck when police found her in the bedroom of her Marietta home.

“Mr. Daker’s hair did not belong, and he is guilty of murder,” Evans said.