Holiday Is Over; Mourning Begins : Shootings: Four people were killed and at least three injured in the Valley during the long Labor Day weekend.

On Hart street in Reseda, a small wooden cross was erected Tuesday bearing the names of Narciso Gurrola and Maria Ortega. Flowers were placed neatly nearby. Mourners prayed or quietly wept.

Gurrola, 20, of Tarzana, and Ortega, 17, of Reseda, were shot to death there Monday, two of the four people killed by gunfire in the Valley over the Labor Day weekend. At least three others were wounded.

Gurrola and Ortega were leaving a party when they were approached by two men who asked if they belonged to a gang. Gurrola said yes, giving the name of his gang, according to LAPD Detective Rick Swanston.

One of the killers then called out the name of a rival gang and shot them both in the back, Swanston said, narrowly missing a third youth with them.

Police said the shooting may have been an act of gang-warfare retaliation by gunmen suspected of involvement in other recent acts of violence.

Administrators at Reseda High School said Gurrola graduated in June, 1994. Ortega, who was enrolled at the school during the 1994-95 year, attended only sporadically before being removed from the school roster in February, they said.

School administrators remembered Gurrola as a talented art student handicapped by his gang affiliation.

“It makes me sick,” said Jeff Halpern, dean of students. “People have no consideration for human life. It’s scary.”

Gurrola’s mother, Rita, said her son had enrolled at Pierce College about a year ago, studying to become a mechanic, and was working two jobs clearing tables at restaurants to pay his way and support his month-old daughter.

In other shootings, Jesus Obeso, 18, of North Hills, was fatally wounded Sunday while riding in a car near Gladstone Avenue and Hubbard Street in Sylmar. A gunman in a dark-colored minivan shot Obeso twice in the head. Obeso died the next day.

In yet another apparent gang retaliation, two men were shot in Sun Valley, critically injuring one of them.

The incident began about 1 a.m. Monday when Phillip Martinez, 26, and Armando Leal, 25, both of Sun Valley, were sitting in a van parked at Cleon Avenue and Saticoy Street. A light-colored sedan carrying two people drove up, LAPD Detective Mike Coffey said. One of the occupants in the sedan asked the standard gang-identity question, “Where are you from?” And then at least two shots were fired.

Martinez was treated for his injuries and released from a hospital Monday, while Leal remained in critical condition Tuesday with head wounds. Neither Leal nor Martinez are believed to be gang members, Coffey said.

Julio Ramirez, 20, of Arleta, and a 16-year-old Van Nuys youth were later picked up in a Pacoima neighborhood by LAPD patrol officers who recognized their car based on a police radio description. Ramirez and the youth were arrested on suspicion of attempted murder.

No motive has been established for the shooting. No other suspects were being sought.

The violence continued on into Tuesday morning, when 23-year-old Luis Alberto Perez was gunned down at a North Hills gas station, LAPD Detective Mike Oppelt said. Perez, of Arleta, was shot to death after he apparently became involved in an argument with two men at a Mobil gas station at Nordhoff Street and Sepulveda Boulevard.

Later, patrol officers spotted a car matching the description of the suspected killer’s vehicle at Devonshire Street and Sepulveda. The officers followed the car onto the San Diego Freeway and pulled it over near Burbank Boulevard.

Julius Rosenthal, 20, and Cyrus Pintor, 26, both of North Hollywood, were arrested on suspicion of murder, Oppelt said. No motive has been established for the killing.

A 40-year-old man also was shot in the West Valley on Monday night. The incident began around 7:15 p.m. when Paula Dever, 32, of Sun Valley, was getting out of her car in the 7800 block of Lindley Avenue and saw her boyfriend, Arthur Corona, wrestling with an assailant, LAPD Detective Larry Dolley said. Corona ran from his assailant, who shot him, Dever said.

The gunman pointed the gun at Dever as well before jumping into a car and escaping. Corona suffered gunshot wounds to his leg and buttock. No arrests have been made.

Obeso’s sister said she was still looking to find out why her brother was killed. “He was a good kid,” Merit Obeso, 19, said of her brother. “He wasn’t in a gang. He wasn’t into drugs. He didn’t dress like a gang member.”

“All I know is that he was in the back seat,” she said. “He got shot from the back of the car.”

Obeso said her brother went out with some friends Saturday night and returned about 11 p.m. or midnight. The last thing she remembers him telling her was that he would be next door watching television with his friends, she said.

She found out later that he decided to go along for a ride when one of his friends was giving another a ride home.

Merit Obeso, who is married and has a year-old son, said her brother, his girlfriend and their 5-month-old daughter were staying with her family in a North Hills apartment.

“He was looking for a job,” she said, adding that he sometimes landed construction work. “I was just helping him out. He was like on his own.

“He was hoping to go back to school and work at the same time for his daughter,” she said. “He wanted to be a general contractor.”

Now, Obeso said, she and her brother’s friends are trying to raise money to bury him.

“We’re low income,” she said. “We don’t have that much money.”