20/20

A wealthy grandmother goes on trial accused in the murder-for-hire of a family member.

A detective stops at nothing – donning disguises, going undercover, employing cutting-edge forensics – to solve the murders of two young women.

From Mr. Right to most wanted: Investigators uncover the double life of an international fugitive.

A teen musician is murdered in her home, another young woman is brutally attacked nearby and the link that helped police catch the killer.

A mother's unwavering crusade for justice after her daughter's murder and the hidden clue that helped catch a killer living in plain sight.

A burned-out car, one victim inside, and a married couple are both missing. Police are left to untangle what happened as they search for answers and a possible killer.

After a young mom is found murdered, seemingly at the hands of a home intruder, investigators uncover a far more intricate plot than the initial evidence suggested.

Four teen girls are found murdered in a Texas yogurt shop. Decades later, DNA evidence and advanced forensics reveal a suspected serial killer.

When a college football player destined for the NFL is murdered, his mother questions whether police have done enough to solve the case. 20/20 and ESPN investigate.

A wedding weekend turns into a real-life whodunit when the vacation rental's host vanishes overnight.

The shocking story of Utah mom Kouri Richins, accused of poisoning her husband and then writing a children's book about grief. The verdict is in. Her closest friend and a jury foreperson speak out.

A woman shoots her neighbor, killing the mother and sparking national outrage. Exclusive "20/20" interviews and body camera video document the bitter feud and its aftermath.

Robert Doerr was a 28-year veteran of the Evansville Fire Department in Indiana. One evening, after returning home from a 12-hour shift, he was shot in his driveway. Police were baffled until a slip of paper hidden inside a condolence card was discovered. The investigation became a family drama, leading a son to turn against his father. Now, in an all-new "20/20," ABC News correspondent John Quiñones reports on what authorities say was a twisted murder plot driven by greed, sex and allegations of an illicit affair. Exclusive interviews with the family and witnesses, along with the body camera footage that captured the vital moments after the firefighter was gunned down as police arrive on the scene on.

Debbie Flores Narvaez was a young woman passionate about dance. Originally from Puerto Rico, Debbie and her sister, Celeste, moved to Maryland with their parents when they were seven and eight years old, respectively. Debbie had dreams of making it big as a Vegas showgirl. After college, she packed her bags and moved to Sin City, where she began auditioning on the Vegas Strip. Soon after, Debbie landed her dream job as an ensemble dancer in the Luxor's "Fantasy," a popular burlesque show in Vegas featuring a rotating cast of top musical artists, including '90s R&B sensation SisQó, who was known for his chart-topping hit "The Thong Song." When Debbie failed to arrive at a midnight rehearsal the night before their premiere, her roommate became concerned and called 911. Friends and family tried to reach Debbie, but she has seemingly disappeared, leaving behind a trail of mystery. "20/20" reports on Debbie's disappearance and speaks with law enforcement officials, friends and family members, and includes an exclusive interview with the person convicted of Debbie's murder in "Death of a Showgirl.

What started as a suspicious house fire in a quiet Cincinnati suburb soon led to something far more sinister. When firefighters arrived at the scene, investigators quickly determined the blaze had been intentionally set, and security footage showed two people appearing to orchestrate the fire. Homeowner Paul Hicks accused his ex-girlfriend of being behind it, but as authorities dug deeper, her alibi held … as did his. The case took a startling turn when evidence, including a custom mask made to resemble his ex and a matching wig, led investigators to question the homeowner himself. Hicks denied that he had any involvement in the arson or the purchase of these items and eventually pleaded to a single misdemeanor count of insurance fraud, receiving a sentence of probation. He was not convicted in connection with setting the fire at his home. Around the same time, investigators were looking at Hicks in the unsolved death of his ex-wife, Regina. In October 2001, she seemingly vanished and was later discovered dead inside her car, which was submerged at the bottom of a pond. Analysis of the vehicle's trajectory undercut a long-held theory that Regina's death could have been an accident, and a witness finally comes forward with startling new information on the person responsible.