TAMPA — When a 1-year-old boy died after suffering massive internal injuries, Tampa police pointed to his 24-year-old pregnant mother as the killer.Quanyisha Thompson, they said, admitted punching her son in the stomach before he died three years ago. She was arrested on murder and child abuse charges.But those charges were quietly dropped this week, days before Thompson was to go to trial. Instead, she pleaded guilty to a charge of child neglect.The reason? The state's case crumbled after every word spoken during a series of police interrogations was barred.The interview tactics of Tampa police homicide Detective Mike Kirlangitis amounted to "coercion, trickery and deceptive police practices," eliciting what may have been a false confession, a defense attorney said. A judge agreed, excoriating the detective in a written order."Detective Kirlangitis suggested nearly every detail of the offense during the interrogation," Circuit Judge Samantha Ward wrote. "The defendant was subjected to a barrage of questions while in an emotionally vulnerable state."• • • On Oct. 1, 2013, Thompson's cousin dialed 911, summoning paramedics and police to the Jackson Court apartments in east Tampa. She said Thompson's son, 1-year-old Joshua Worthy, was not breathing and his eyes were rolling back in his head.The baby was rushed to Tampa General Hospital. He was dead when he got there. Thompson told police and an investigator from the Department of Children and Families that her son had recently been vomiting and had a fever. She didn't take him to a doctor, she said, because she had no insurance, according to a DCF report. She gave him over-the-counter medicine.Thompson said the boy had been sick since shortly after a Sept. 28 visit with his biological father, who had just been released from prison. She also said the baby would cry any time he was around her current boyfriend, who she said was known to "pop" her children.An autopsy showed Joshua had ruptured internal organs and several broken ribs in various states of healing. DCF placed Thompson's three other children in protective custody.Kirlangitis conducted five interviews with the mother the day her son died and in the days that followed. Court records describe her as distraught, crying and vomiting at times.In the fifth interview, she finally told Kirlangitis she had punched her son in his stomach and chest. A murder charge came a month later, after she had given birth to another child. Thompson was jailed without bail. Meanwhile, her interviews with Kirlangitis became the focus of intense scrutiny.In a court motion filed last month, Assistant Public Defender Dana Herce-Fulgueira accused the detective of misleading Thompson into a confession.The defense attorney said Kirlangitis suggested details of the crime to Thompson and hinted that unless she told him what happened she might not see her other children again."Don't make me pull this out of you because it's already hard enough . . . for me to figure out what the heck the truth is," Kirlangitis said, according to court records. "Now I'm not in here pointing fingers. I'm in here telling you what happened. . . . You don't get a ton of opportunities to tell me what the heck really happened."He also told Thompson not to discuss the case with anyone but him, a suggestion that could have made her think she was unable to talk to a lawyer, according to the court motion.Gregory DeClue, a forensic psychologist, examined Thompson in the Falkenburg Road Jail. A test he administered pegged her IQ score at 77, reflecting an intelligence level lower than that of 94 percent of adults.The psychologist also found Thompson to be more susceptible to misleading questions than the average person.DeClue's report on the case criticized the detective's tactics. It noted that Kirlangitis told Thompson she wasn't in trouble and that this was not a criminal investigation before saying that she was certain to be arrested. The report also quotes portions of the interviews in which Kirlangitis tells Thompson to talk only to him."You're not going to tell anybody what we discuss about, you hear me?" he said, according to the report. "You promise me you're not going to say nothing!"Later, the detective relayed details of the autopsy findings. He demanded answers from Thompson that would match those details, according to the report.It was in the final interview that Kirlangitis confronted Thompson with photos of her child's dead body. That's when she said she had punched the boy, something the detective had repeatedly suggested to her.In that last interview, he told her she had the right to remain silent and the right to an attorney.She said she had never heard that before.• • • While in jail, Thompson was prescribed medication for depression and anxiety, according to court records. The court case took three years due to considerable legal maneuvering, much of it related to whether the police interviews should be suppressed.In a March 14 order barring them from trial, Judge Ward noted Thompson's emotional fragility at the time she was questioned. The judge also noted that every time Thompson replied, "I don't know," the detective would offer scenarios of what could have caused the baby's injuries."Most offensive and troublesome to this court," Judge Ward wrote, "was showing the defendant autopsy photographs of her own child and re-enactment of what the baby might have done in response to 'the punch.' "Kirlangitis is now a corporal with the Tampa Police Department, though he no longer works in homicide. Tampa police spokesman Steve Hegarty said the department respects the judge's decision but declined further comment.As for Thompson, she is now free, having been sentenced to time already served. Her children remain in the care of relatives.Contact Dan Sullivan at [email protected] or (813) 226-3386. Follow @TimesDan.