The brutal murder of Deborah Dalzell in 1999 gripped the world. Now, detectives have arrested a suspect with an ingenious method.

For almost 20 years, the gruesome murder of Deborah Dalzell gripped the United States.

In 1999, the woman's badly beaten body was found in the bathroom of her Florida home.

This week, after a lengthy investigation, police finally found and arrested a suspect — 39-year-old Luke Fleming, who had lived within walking distance of her home.

Advertisement

Those who spent years piecing the puzzle together described it as one of the most brutal murder cases they had never witnessed.

WHAT HAPPENED TO DEBORAH DALZELL?

On March 29, 1999, detectives were called to Dalzell's home on Colony Meadows Lane in Sarasota after she failed to show up for work at KMC Telecom, where she was an office manager.

Inside, detectives made a gruesome discovery — the woman had been brutally beaten, sexually assaulted and strangled, with her body left to rot in her own home.

The night before the incident, Dalzell's sister, Peggy Thistle, had invited her out to dinner, but she declined. She'd been working long hours that week and wanted a quiet night in, the Herald-Tribune reported.

Dalzell's last conversation with her sister was on the phone at around 10.30pm that night.

According to the Tribune, Dalzell's home was in a mostly incomplete subdivision. When she slept she left some interior French doors open.

Detectives noted she often slept with the windows open, and had a "false sense of security".

Passers-by on Honore Avenue, adjacent to her street, had an unobstructed view into her bedroom.

Sometime between her phone conversation with her sister and 6am the next morning, a man stood on the pool pump and climbed a 1.8m wall up to the woman's home.

He cut open a flyscreen and entered the pool area, then went into her house through the open French doors. He found Dalzell in bed and started to beat her fiercely.

The following morning, when she failed to show up for work, Dalzell's co-workers became concerned. One of them went to her home, saw her bedroom in disarray, and called the police.

Detectives went inside and found her body in the bathroom in a shocking state. Dalzell had been sexually assaulted, her jaw dislocated, and she was left with terrible bruising. It was clear that she had put up a struggle.

For a long time, investigators grappled with who was responsible. Semen was collected from the site of the murder, but initial tests yielded no results.

Detectives believed she was killed by a stranger. She was a "workaholic" with no romantic relationships, authorities said, and mostly socialised with her family.

"She was a creature of habit, not a huge risk-taker," her sister said.

"It's so huge for us to still come to grips with — that this soft-spoken, wonderful, special person met with someone who murdered her."

HOW THE SUSPECT WAS FINALLY CAUGHT

It took more than 19 years to arrest a suspect.

In 2015, detectives sent the DNA evidence from the crime scene to Parabon NanoLabs in Virginia. The company specialises in DNA phenotyping — a form of DNA analysis that can predict physical appearance and ancestry.

It produced a mock-up of what the suspect would have looked like at around 25 years old.

"In this analysis, the suspected DNA was compared to a database of DNA profiles from volunteer participants in an effort to identify relatives of the suspect DNA and how closely they were related," Captain John Walsh said.

This is how detectives identified Luke Fleming, now 39, who lived within walking distance of Dalzell's home at the time of the murder.

Last year he moved to St Petersburg, on Florida's gulf coast, but he was arrested in Ellenton, a town around 25km away.

Fleming had one case of domestic battery on his record from 2002, but otherwise his criminal history was unremarkable.

His family denied any comment on his arrest, but according to local reports, friends said he was an average man who "seemed like a good father". One said he never gave the impression that he was capable of such a horrible crime.

Speaking at a press conference earlier this week, Thistle said: "We miss Deborah every day. We never gave up hope. We're still processing this development. We say, for 20 years, he has been able to see the sun, breathe the air, smell flowers. May today be the last day."

Two decades later, the murder suspect is now in Sarasota County Jail with bail set at $1.2 million.