Shanann Watts' father, Frank Rzucek, spoke to reporters on Monday.

Frank Rzucek, whose daughter and grandchildren were killed by son-in-law Chris Watts, says "heartless" bullies are trolling his grieving family online.

Chris Watts was sentenced in November to life without parole.

Chris Watts told investigators he was triggered into a rage after wife Shanann Watts accused him of cheating and told him that he'd never see his children again.

Chris Watts was sentenced in November to life without parole for the three murders.

Search warrants were recently released in the murder investigation of Kelsey Berreth, whose fiance is under arrest for her murder.

Chris Watts was sentenced in November to life without parole for killing his wife, Shanann Watts, 34, and their daughters Bella, 4, and Celeste, 3.

Shanann Watts' parents confronted him in court at his sentencing hearing, where he was sentenced to five life sentences without the possibility of parole, serving three consecutively.

After investigators uncover the grave of Shanann Watts and the gruesome disposal of the girls, her husband Chris Watts pleaded guilty to their murders.

While sitting in a police interrogation room, Watts claims to his father that he killed Shanann Watts after she had strangled their kids, but investigators weren't buying his story.

While friends say Shanann Watts was trying to repair her marriage, her husband was having an affair with a woman he met through work.

Shanann Watts is gone without a trace, leaving behind her cell phone, purse and wedding ring. Meanwhile, her husband pleads for his family's return.

Their lives are enviable for many following Shanann Watts on social media, until the community's perception of their happy family is shattered when Shanann and her daughters go missing.

The parents of slain Colorado pregnant woman told “20/20” that they are still grappling with why their son-in-law Chris Watts murdered their daughter and granddaughters.

20/20 Extra: Interrogation video shows Chris Watts speaking to investigators about his missing wife and two kids and his shocking confession about how he killed his wife.

Shanann Watts' parents react to his now-infamous plea on television for his missing wife and two daughters to return.

Authorities say a neighbor's security video shows Chris Watts making three trips from the house to his truck carrying something the morning his wife and children disappeared.

Nickole Atkinson, who saw Shanann Watts at 2 a.m. Monday before she went missing, says Watts' husband seemed unconcerned his wife and daughters were missing.

The friend said she wasn't surprised when Chris Watts was arrested on suspicion of murdering his wife and two young daughters.

Shanann Watts' body was found in a shallow grave near an oil tank, according to court documents filed in Weld County and obtained by ABC News.

The Weld County district attorney charged Christopher Watts with the murders of his wife and daughters.

The mother was found in a shallow grave and the girls were concealed in nearly full oil tanks, according to authorities.

Nickole Atkinson was a close friend of Shanann Watts, the woman who was found dead along with her two young daughters, Celeste and Bella.

Court documents revealed Chris Watts was having an affair with a co-worker and he wanted a separation, but now he claims his dead wife Shanann Watts killed their two daughters.

A judge read the nine felony charges to Chris Watts, 33, after he allegedly admitted to killing his pregnant wife Shanann.

Chris Watts, charged with the murders of his wife and two daughters, had a video on his Youtube channel six years ago in which he discussed why relationships fail.

Chris Watts originally told reporters the trio disappeared without a trace; he faces up to life in prison with no possibility of parole.

A judge sentenced Chris Watt to five life terms for the murders of his pregnant wife and two children after his in-laws took the stand in court on Monday.

Text messages, police interrogations and other details emerged in a new crop of documents released after Watts pleaded guilty and was sentenced for killing his wife and their two daughters.

Watts, also charged with killing his two daughters, is seen with his father in a police interrogation room blaming the death of the couple's daughters on his wife, Shanann Watts.

Chris Watts sent a woman love letters while keeping appearances as a family man.

Prison officials said they were not disclosing Chris Watts' new location.

Chris Watts had initially said his wife, 34, disappeared without a trace.

Chris Watts received five life sentences after confessing to killing his family.

Chris Watts was arrested in the killing of his wife and daughters ages 3 and 4.

The victims' family agreed to the terms in exchange for Chris Watts' guilty plea.

Shanann Watts and her two daughters were allegedly killed by Watts' husband, Chris.

Prosecutors say Cristhian Rivera confessed to kidnapping and killing her.

The suspect in the Iowa murder case made his first court appearance as prosecutors say he kidnapped and killed college student Mollie Tibbetts while she was jogging.

After a nearly five-week search, authorities discovered the body of Mollie Tibbetts, who was allegedly murdered by an undocumented immigrant. ABC News' Lynda Lopez reports.

Iowa Division of Criminal Investigation is revealing how surveillance video led to man suspected of murdering the 20-year-old Iowa student.

Chris Watts, accused of strangling his family to death, appears in court.

Watts claims after seeing his wife strangling one of the kids on a baby monitor, he strangled their mother inside the family's home, according to court documents.

Chris Watts faces three murder charges and was denied bond.

Christopher Watts claims he killed his wife after she strangled their daughters, but was charged with all three murders.

Shanann Watts' father was overcome with emotion in a Colorado court Tuesday, crying with his head buried in his hands as murder charges were read against his son-in-law.

Chris Watts is accused of killing his pregnant wife, Shanann Watts, and their two daughters, Celeste, 3, and Bella, 4, last week.

The Colorado husband charged with killing his family has blamed his wife, claiming he only killed her after she strangled their children. ABC News' Kendis Gibson reports.

Husband allegedly claims that his wife strangled their daughters, police said.

She said she wasn't surprised when cops named her friend’s husband as a suspect.