'Fledgling serial killer' Michael Tanzi to be executed for woman's brutal murder. Who is he?

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A Florida death row inmate set to be executed on Tuesday began his life of crime in his home state of Massachusetts and was, according to one local detective, a "fledgling serial killer."

But Michael Tanzi's attorneys say a childhood filled with abuse and trauma led him down a violent path and that he deserves to be spared from the death penalty.

Florida is set to execute the 48-year-old Tanzi by lethal injection for the 2000 rape and murder of former Miami Herald employee Janet Acosta. If the execution moves forward, Tanzi will be the third inmate executed in the state this year and the 11th in the U.S.

Tanzi’s lawyers have been arguing that he shouldn't be executed because of developmental issues and health problems stemming from being morbidly obese.

Prosecutors say Tanzi doesn't deserve mercy and that Acosta's murder can “only be described as horrific.”

As the execution approaches, Paste BN is looking back at the crime, who Tanzi is, and who his victim was.

What was Michael Tanzi convicted of?

On April 25, 2000, 49-year-old Janet Acosta was on her lunch break, eating in her van at a favorite spot, under a shade tree next to the Japanese Rock Gardens in Miami, according to court records.

Around 1:30 p.m., Tanzi attacked Acosta, forcing his way into her van, tying her up and threatening to kill her if she resisted, according to Tanzi's confession to police.

Prosecutors say Tanzi then drove Acosta 30 miles south to Florida City before parking at a gas station, where he raped Acosta while threatening her with a razor, he confessed.

"I told her I'd slice her neck," he told police. ""I told her that I'd cut her from ear to ear."

Tanzi then began driving south again, promising Acosta that he would release her once he reached Key West, Tanzi told police. On the way, Tanzi stopped at multiple ATMs and used Acosta’s card to get some cash.

When Tanzi reached Cudjoe Key, about 20 miles shy of Key West, he strangled Acosta and buried her in a secluded place. Prosecutors said that Acosta's kidnapping lasted about four hours before the murder.

“If I had let her go, I was gonna get caught quicker," he told police during a confession. "I didn’t want to get caught. I was having too much fun ... I told her, I says, 'I can’t let you go. If I let you go, then I’m gonna be in a lot of trouble.’”

Tanzi spent the next two days shopping, buying a new wardrobe, marijuana and food. Police officers arrested Tanzi after seeing him get into Acosta’s van in downtown Key West.

Police recovered Acosta's body after Tanzi showed them where he buried her.

Janet Acosta was not Michael Tanzi's first murder victim: Police

Tanzi began committing a string of crimes in the suburbs of Boston as a young man. He was arrested in 1998, when he was around 21 years old, after stealing a van and breaking into a home in the Boston suburb of Brockton.

He was sentenced to 18 months in prison but only served six months and was released in August 1999.

After Tanzi's arrest for Acosta's murder, police say he confessed to killing Caroline Holder in Brockton, Massachusetts just a few months earlier, according to court records.

Holder was stabbed to death and beaten while she was working at a laundromat, according to reporting from the Tampa Bay Times.

"What we have here is a fledgling serial killer," Miami police Detective Frank Casanovas said at the time, according to an archived story in the Miami Herald.

Tanzi never faced extradition for Holder's killing because of his death sentence for Acosta's murder.

'My best friend': Tough, world-traveling Miami woman's murder devastated family, friends

Michael Tanzi's attorneys describe troubled childhood

Born in 1977 in the suburbs of Boston, Tanzi's attorneys describe his childhood as one full of loss, abuse and a lack of stability. They say he was sexually molested by a childhood friend and physically and emotionally abused by his father.

Tanzi's father became more violent toward his son as he was diagnosed with pancreatic cancer. According to Tanzi's mother, the abuse made Tanzi become more disruptive, angry and troublesome, according to court records.

One of Tanzi's friends said that Tanzi’s father once slammed the boy's head into the side of a truck, according to court records. Meanwhile his mother was "not home that much," according to the friend.

Tanzi also had many problems in school, academically and socially.

“Mike didn’t get along with too many kids at all," his mother said, according to court records. "He was always angry or fighting with them over something."

When Tanzi was around 11, his mother tried to take him to a meeting for sexual abuse victims, something he was vehemently against.

“He didn’t want to face it," she said. "He didn’t want to talk to people about anything that had happened to him."

Michael Tanzi’s lawyers say he is too big to be executed

In appeals filed by his lawyers in recent weeks, Tanzi’s lawyers have argued that he shouldn't be executed because of his complicated health condition.

In a filing with the Florida Supreme Court, Tanzi’s lawyers describe Tanzi as a morbidly obese man with sciatica, a nerve condition they say affects his back and could cause him to suffer pain leading up to a lethal injection because he'd have to lie down and be restrained.

“Being in this position and suffering 'severe sciatic nerve pain' would require DOC ‘to torture him simply to establish and maintain two working intravenous sites,’” Tanzi’s defense lawyers said.

They also argued that Tanzi’s size could cause a sedative to not work, which would allow him to experience pain.

The Florida Attorney General’s Office argued against those concerns.

“Tanzi fails to offer any support for his groundless assertion that the massive dose of etomidate, that has been repeatedly and successfully used in Florida’s lethal injection protocol, will not work for him,” court records said.

The Florida Supreme Court sided with the state and rejected Tanzi's concerns last week, meaning his last hope for a reprieve lies with the U.S. Supreme Court or through a pardon by Republican Gov. Ron DeSantis, who signed Tanzi's death warrant in March.

Fernando Cervantes Jr. is a trending news reporter for Paste BN. Reach him at fernando.cervantes@gannett.com and follow him on X @fern_cerv_.