Partiers began to arrive at Hector Cortes’s San Marcos home about 5:00 p.m. His common-law wife had decorated the garage with a “Happy Birthday” banner and set up chairs and a big table for food and cake. Cortes had turned 46 years old on August 19, 2009, which was a Wednesday. His party was the following Saturday.

All 15 people who lived in the four-bedroom, rented home — seven adults and eight children — took part in the early fun. At the height of the party, maybe 25 to 30 revelers attended.

One of the housemates, 20-year-old Alfonso Gomez, arrived a couple of hours after the party started. Cortes said he handed Gomez a Corona beer, opening the bottle with a folding knife that Cortes always carried in his pocket.

Within a few hours, Cortes would use the knife to pierce Alfonso Gomez’s rib cage.

Cortes apparently had mixed feelings about Gomez. Although Cortes claimed they were friends, a year and a half earlier he had talked to another man in the household about calling the police on Gomez.

In February 2008, Gomez had fought with a 15-year-old boy who lived in the house. The boy later remembered, “We fight about, just, the TV.” The teen said he changed the channel on the television they both were watching and Gomez punched him. “He hit me. On my face. Like, three times or four.” The boy said his uncle phoned the police, deputies came, and they photographed a mark on the teenager’s face.

After he heard about this incident, Cortes said he spoke to Francisco Carrillo Cruz, who had rented the home since 2005 and collected money from the others to pay the rent. Cortes later said in court, “I told Francisco he should call the police.” Cortes felt Carrillo “had an obligation to set order in the house.” But Carrillo said he didn’t want any problems with the police or immigration.

Carrillo testified that about a month before the birthday party, Cortes told him, “One of these days, I’m going to get that boy drunk, and we’re going to get into it and I’m going to stab him in the heart.” Carrillo relayed this to detectives later, but Cortes denied ever making this statement.

The night of the birthday party, August 22, 2009, Alfonso Gomez celebrated with Cortes and the others, drinking beer, enjoying the music, and dancing. Sometimes he danced by himself, and sometimes he danced with the women.

Before he danced with Leticia Valdez, he asked permission from her common-law husband Juan Rosales. “If that’s her wish, you can dance with her,” Rosales responded, according to his testimony later.

Rosales said he drank “one 18-pack” of beer at the party. Leticia Valdez later estimated that she drank 20 beers that night. Although she danced with Gomez, she said that he “was being insistent” about dancing with women at the party, which was “bothering.” She said that her husband told Gomez to leave her alone.

In court, Juan Rosales explained the scuffle that developed between himself and Alfonso Gomez this way: “We just accidentally ran into each other physically.”

Didn’t Alfonso go to the ground? the prosecutor asked.

“I just pushed him, and he fell down, and that’s it.”

Some of the people at the party said Rosales punched Gomez twice in the head.

Rosales departed, although Hector Cortes tried to persuade his friend to stay at the party. Leticia Valdez declined to accompany her husband, later saying variously that he was too drunk to drive and that she wanted to avoid an argument with him.

But Cortes testified that he told Leticia Valdez, “You should have left with your husband.”

The woman responded that Cortes was stupid, an idiot, a good-for-nothing, and a coward.

Twenty-year-old Alfonso Gomez found this harangue funny.

“He started laughing and mocking me and repeating the same words,” Cortes said.

Cortes told the 20-year-old that if someone were disrespectful to his wife, he would kill him, according to Leticia Valdez. But Cortes remembered the conversation as “I told him, if you had a wife, would you like it if someone were bothering her?”

Cortes testified that he became angry. According to witnesses, Cortes put Gomez into a headlock, with his left arm around Gomez’s neck, and he punched Gomez with his right fist.

In Cortes’s version, it was Gomez who threw the first punch, and there was a struggle and the men grappled.

Leticia Valdez does not remember breaking a beer bottle over the back of Cortes’s head, although others at the party saw this. Glass and beer sprayed everyone nearby.

“I felt a blow being dealt to my head,” said Cortes. “It felt wet. I thought it was blood.

“I got scared, I felt fear, I felt I was being wounded,” he said.

“I pulled out the knife to scare Alfonso,” Cortes testified. “To show it to him. To scare him. I was just protecting myself from what was going on. Suddenly I felt my hand was wet.” Cortes said he looked at his hand and saw blood. He said he threw the knife away. A bloody knife was later found resting underneath a couch at the back of the garage.

“I did not want to injure him,” said Cortes. “I stood up, and he did not. He appeared to be fainted.

“I got scared. I was fearful. I got nervous. I heard voices. They were saying, ‘Don’t let him leave, don’t let him leave.’

“I grabbed the keys to my truck; then I drove away.” Cortes said he was “driving aimlessly.... I only realized I was approaching Mexico when I got stopped.” Cortes said he was born in Mexico and attended seven years of school there.

1:12 a.m. 911 received a call describing a stabbing.

1:24 a.m. Emergency responders declared Gomez dead on scene.

1:26 a.m. Deputies contacted border stations, alerting them to look for a white Ford F-150 pickup truck driven by a Hector Cortes.

2:05 a.m. Border Patrol detained Hector Cortes at the Otay Mesa border crossing.

Border Patrol officer Scott Guernsey said he stopped a white Ford truck and asked the driver where he was going. The man said he was “going to Mexico.” Guernsey asked where he came from. “San Marcos.” The officer asked for some ID and was handed a driver’s license for Hector Cortes. The officer noticed the driver had blood on his hands and clothing. “We extracted him from the vehicle,” Guernsey testified later.

A photo of the stab wound on Alfonso Gomez’s chest shows an imprint made from two little knobs that protrude from either side of the blade on the knife that was recovered. A prosecutor said the red marks indicate the heavy force of the blow from the attacker, who drove the blade in as far as possible. When the prosecutor asked Hector Cortes if he used “maximum force” to cause such a mark on Gomez’s body, the defendant answered, “I didn’t realize the force that I used.”

Cortes said repeatedly during his murder trial that it was not his intention to kill Gomez.

Gomez was 5 feet 3 inches and 149 pounds at the time of his death. A blood test showed his alcohol level at .21 percent. The autopsy revealed a single stab wound four inches deep, passing through the cartilage of his third rib before it invaded both sides of his heart.

Hector Guatemala Cortes was held in lieu of $10 million bail. Cortes was 5 feet 4 inches and 185 pounds. Five hours after Gomez’s death, Cortes’s blood alcohol level was .10 percent.

In early October 2010, toward the end of a five-day trial, during which most of the witnesses, as well as the accused, testified using an interpreter, Cortes’s defense attorney addressed the jury. Deputy public defender Lacey Martz said the incident was “tragic and sad,” but it wasn’t murder. She asked the jury to “consider Mr. Cortes’s use of alcohol” when deciding his degree of culpability.

The prosecutor, Deputy District Attorney Minaz Bhayani, asked the jury to find Cortes guilty of first-degree murder. “Hold him fully accountable,” said Bhayani. “Don’t let him plea bargain his case to you.”

The judge told the jury in his instructions that “provocation” may reduce a murder from first degree to second degree. The jury of three women and nine men deliberated about three hours.

On October 6, Cortes was found guilty of second-degree murder.

The judge who heard the trial, the Honorable Aaron Katz, will pronounce sentence on Hector Cortes on January 11 in the Vista courthouse. ■