When Evelin Ventura brought her youngest child to the hospital in January 2009, the 8-month-old girl was emaciated, her enlarged head was bulging, and she was lethargic, vomiting and clearly in pain.

Ventura, 29, of Dumfries, said the infant girl had been riding in a stroller that tipped over, causing the baby to hit her head on the ground. Though doctors thought the injuries were more consistent with a violent shaking, social workers, Child Protective Services investigators and police determined that no abuse had occurred. Permanently blinded and with parts of her brain dead, the little girl went home with her mother.

Prince William County prosecutors argued in circuit court over the past week that Ventura’s baby returned into the care of a “tormenter,” a mother so upset that the baby even existed that she repeatedly abused her during the first two years of her life. Ventura escaped detection, they said, by lying to authorities and slipping through a system that repeatedly failed to identify what they called a pattern of chronic abuse.

“A lot of people let this child down,” Assistant Commonwealth’s Attorney Sandra Sylvester told jurors. “The police, social services, occupational therapists, doctors, and the one person who should care for her, her mother, the defendant.”

On Wednesday, jurors found Ventura guilty of four counts of felony child abuse, one count of aggravated malicious wounding and two counts of assault and battery. Jurors recommended a prison sentence of 34 years and a $100,000 fine; under Virginia sentencing rules, Ventura would be behind bars until after her 55th birthday should Prince William County Circuit Court Judge Mary Grace O’Brien ­uphold that sentence at a hearing scheduled for June 8.

The case, one in a stream of such child abuse trials in local courts, highlighted the path that Prince William County has followed in the three years since the high-profile death of Lexie Glover. Lexie, a special-needs girl known to police and social services officials, was left for dead in a frigid creek by her mother in January 2009. It was just days before Ventura brought her daughter to the hospital for her head injury.

Lexie’s death, and the shortcomings it identified, led authorities to rethink the county’s treatment of at-risk children and spawned a revamping of the way police investigate abuse. New protocols and training, police officials say, ensure such cases do not go uninvestigated.

With that new approach — involving social workers, doctors, more frequent forensic interviews and a team of detectives assigned to such cases — Ventura was arrested about a year after she brought her daughter to the hospital for the head injury. An observant day-care worker noticed scratches and bite marks on the baby’s body, and Prince William County police Detective Dan Harris delved into the girl’s history and interviewed her mother, who admitted some of the abuse.

A thorough examination of Ventura’s baby turned up two old elbow fractures and injuries a doctor said were too numerous to count. Authorities said they believe the intervention likely saved the baby’s life.

First Sgt. Liam Burke, who leads the county police’s Special Victims Unit, said Lexie’s case was a “learning experience” that helped refocus police efforts at protecting children and arresting abusers. Detectives received new training in early 2010 and since have looked more carefully at each case.

“We’re looking at the totality of the circumstances, the history, full forensic interviews,” Burke said outside of Circuit Courtroom 3 in Manassas on Monday, just after Judge O’Brien sent Ventura’s case to the jury.

After Ventura’s three children were taken from her, she was indicted, pleaded not guilty and testified at trial that the major injuries to her daughter were ­accidental; she said the girl fell off a bed and out of a stroller. The scratches were her fault, she said in Spanish through an interpreter, because she was “frustrated.”

Ventura had been secretly living in an abandoned house because she was homeless, had no family support, was unable to properly care for her children, and was nearly penniless. Having a special-needs child who would cry incessantly pushed her to the brink, she and her defense lawyer, Margaret DeWilde, said in court.

“I felt that I had asked for all the help I could, and I felt I couldn’t go on any longer,” Ventura testified. “I didn’t know what else to do.”

So when her baby was brought to the hospital in June 2010 with the scratches and bite marks, Ventura said she lied and blamed another child for the injuries. She was afraid of losing her children, Ventura said. And as an undocumented immigrant from El Salvador, she also risked deportation if convicted of a crime.

DeWilde argued that Ventura was a victim of poverty and was overwhelmed, leading her to miss doctor’s appointments for a baby she loved and wanted to care for but lacked the experience to do so. She noted that the early cases were investigated and resulted in no charges.

“If CPS had felt there was an issue with child abuse, they could have done something in June 2008,” DeWilde said, referencing the baby’s first visit to the hospital, at 8 weeks old, when she was vomiting, crying and had bruising on her face, which doctors said was consistent with someone having grabbed her forcefully.

Prosecutors credit Harris with cracking the abuse case after he saw the baby in June 2010 and she appeared “very wasted away, emaciated” and with scratches and bite marks nearly from head to toe. Ventura initially denied hurting her daughter but later broke down and said she lost control when the baby was inconsolable.

Sylvester and Assistant Commonwealth’s Attorney J. Regan Kline argued that Ventura was vengeful and sadistic, upset at the fact that her daughter’s father was a married man who would not leave his wife to care for them. Kline told jurors that Ventura’s youngest child was a “target” of her frustrations, and that she alone suffered malnutrition, physical abuse and neglect. Ventura’s other two children were healthy and well cared for, according to testimony.

The baby survived the abuse, and she has since been living with her biological father. Though permanently blind and developmentally delayed, she is happy, healthy and playful, as seen in videos and photographs at trial. “The difference is, her tormenter has not had access to her,” Sylvester said in court. She later ended her closing argument near tears: She “will never be able to fully comprehend what her mother did to her. That is a life sentence.”