Phoenix man who tried passing off girlfriend's murder as suicide is sentenced to 20 years

After trying to make his girlfriend's death look like a suicide, a Phoenix man was sentenced to prison for her murder on Friday.

Guillermo Diaz Jr., 43, was given a 20-year sentence by Maricopa County Superior Court Judge Lisa Ann VandenBerg for his second-degree murder conviction in the death of Corina Leyva, 41. He accepted a guilty plea in March.

In 2021, Diaz shot and killed Leyva in his north Phoenix home after they had an argument, he confessed in court. He placed the gun next to Leyva's hand to make it look like a suicide, but his 7-year-old son saw the incident unfold and told the story that Diaz later admitted to.

Friday's sentencing was filled with testimony of who Leyva was, the domestic violence issues within Diaz and Leyva's relationship, the hardships Leyva's family has gone through after leaving behind six children and Diaz's character.

What happened in 2021?

The following account is based on court documents and testimony.

A little after 4 a.m. on July 3, 2021, Phoenix police were called by Diaz, who reported that Leyva had committed suicide by shooting herself in the head. When police arrived, they found Leyva lying on the floor of Diaz's bedroom with a shot to the head and a gun next to her right hand. They declared her dead.

The initial story Diaz told was this: Leyva, Diaz, and his 7-year-old son were lying in bed. Diaz told police that Leyva suddenly became upset, so she got up and said that she did not want to be there anymore. Diaz had a gun in his dresser drawer — something he was not supposed to have because a prior felony conviction prohibited him from possessing a gun. Diaz told police that Leyva pointed the gun to the back of her head, according to court records.

Diaz said he tried to take the gun from her, but Leyva ended up shooting herself before he could do so.

But that story didn't hold up. Diaz's son said he saw the whole thing and told family members, officers, and first responders that Diaz lied and actually killed Leyva.

In an interview with investigators, Diaz's son described how Diaz grabbed Leyva, hit her, and the son heard a shot. The son said he saw Diaz holding the gun after Leyva fell to the floor.

However, Diaz stuck with his story in his interview with police. He told investigators that he and Leyva had been drinking earlier in the night and began arguing about suspicions of infidelity. The couple continued arguing in Diaz's bedroom when Leyva became upset, got up, and grabbed the gun.

Diaz said he grabbed the gun, struggled, and fell. While he was falling and the gun was in his hand, Diaz said the gun fired a round and hit Leyva in the head. He first said he did not know how the gun ended up next to Leyva's hand, but later admitted to moving it there before police arrived.

Diaz said it was an accident and told police he lied because he was afraid. He was arrested the same day.

Arrest records show that a domestic violence incident had been previously reported between Leyva and Diaz.

A tormented relationship described in court

A total of 22 family and friends filled up the courtroom on Friday — 12 for Leyva and eight for Diaz. Diaz was in an orange jumpsuit and, from behind, looked like his head was tilted slightly downward for most of the hearing.

Leyva's family, specifically her sister, mother, and niece, dug deeper into the domestic violence issues between Leyva and Diaz. Leyva's mom told the court about seeing her daughter's bruises, despite Leyva trying to cover them up with makeup. Leyva's niece testified that the family knew about "the beatings," and that they knew "everything," with one of Leyva's daughters commenting from the gallery, "Everything!"

Leyva's sister, Betty Leyva, spoke powerfully to the court about Diaz and Leyva's relationship, while occasionally casting glances in Diaz's direction.

"I would like the court's records to reflect that my ultimate goal and presence here in this courtroom today is justice for my little sister Corina Leyva."

She said that from the beginning, the family did not have a good feeling about Diaz after Leyva met him in January 2021. He was still living with his mother, had no job, was behind on his house, and made himself the victim for issues he wouldn't take accountability for, according to Betty Leyva.

So, Leyva helped him out. Betty Leyva said her sister helped Diaz out financially and helped him fill out unemployment paperwork and child support responsibilities — all for him to get back on his feet.

That ended up costing Leyva her life, her sister told the court.

"What he (Diaz) did not expect was that this little act of his would wind up giving my sister Corina the upper hand in this toxic relationship. Now, he owed her money," Betty Leyva said.

She added that Diaz's insecurities grew, resulting in domestic violence situations with Leyva. She said Leyva told the family that Diaz once said he was going to kill her if she left him.

Betty Leyva said that Leyva finally broke up with Diaz the night of the incident. But, Diaz wanted to meet up with Leyva and threatened that if they did not meet, he was going to hurt her children, Betty Leyva testified. He accompanied that message with a picture of him outside of her home.

"So my sister, the protector that she was for her children, agreed to meet him at his mother's house where he then took her life," Betty Leyva said.

Leyva's daughter, Maryann Lopez, also spoke. She praised Leyva not only as being a mother, but a sister, aunt, daughter, grandma, and friend. Lopez said Leyva was such a selfless person who would bend over backward for anyone who needed it. Lopez then turned to face Diaz and said, "Like she did for you."

Lopez said since her mother's death, she is a co-guardian for her three younger siblings with Betty Leyva.

Three of Diaz's friends made statements. One said he never knew Leyva to do things that were described by Leyva's family. He described Diaz as someone who was always there for him and that they attended the same men's Bible study where the group would try and talk through their problems together.

Another friend was one Diaz knew since childhood. He said he knew Leyva well because they all had dinner together often. He said he would give Diaz and Leyva relationship advice and had once told them that they might not be the best for one another because they were both strong-willed people.

Diaz's mother and sister were in the gallery but did not make a statement.

After the sentencing, Leyva's family gathered together in the hallway. At one point, a group of them hugged Betty Leyva because of her strong statement to the court.

Betty Leyva told The Arizona Republic she wished the state was more assertive with the sentence because of Diaz's past and because of what he did.

Diaz's plea agreement stated that the maximum sentence he could have received was 25 years.

But now, Betty Leyva says the family is just looking forward to moving on and turning the page.

Maryann Lopez said in an interview that it's important to be observant of the people in our lives. Leyva's niece said in her statement that Leyva hid from the family for two days because she was ashamed of her bruises. Lopez wants people to know they should support and love those who are in a tough spot, because it's never known what's happening behind closed doors.

Betty Leyva had a message for young girls, but it can apply to anyone.

"If any young lady or young girl is in an abusive relationship, the first and immediate thing to do is to get away from it."

This reporting follows crimes The Republic began to cover in 2021 and is part of our commitment to telling the story from start to finish.

This article originally appeared on Arizona Republic: Phoenix man gets 20 years in prison for 2021 murder of girlfriend