A back-and-forth San Fernando Valley dragnet for a man accused of shooting to death his dad and a brother in a Canoga Park apartment, a woman acquaintance at a North Hollywood gas station and finally a passenger on an Orange Line bus ended just two miles from where the spree began nearly 12 hours before on Thursday with his arrest.

Along the way, besides those four who were killed, the suspect’s mother was shot, and so was another man in North Hollywood, police said.

At about 2:30 p.m. Thursday, 26-year-old Gerry Dean Zaragoza was arrested near Canoga Avenue and Gault Street after police blamed him for those crimes as well as an attempted robbery of another man at a bank.

Speaking shortly after the arrest, Kris Pitcher, chief of detectives for the Los Angeles Police Department, said police soon put together that the two shootings on opposite ends of the Valley were linked, though he wouldn’t spell out exactly when they figure that out, or why they focused on Zaragoza.

“After we had multiple killed in a short time, we put significant investigative resources on this,” Pitcher said. “It was pretty quickly that we discovered they were related.”

The chaos began at around 2 a.m. when the suspect shot his family members, police said. His mother, after suffering a gunshot wound, was is in stable condition.

Less than an hour later, Zaragoza is accused of shooting the female acquaintance and another man at the North Hollywood gas station, killing the woman. The man was shot several times – but survived, detectives said.

At 7:30 a.m., in the midst of all of the violence and a mile and a half from the family apartment, Zaragoza tried to rob a man outside a Bank of America, police said, but failed when he discovered the victim had no money.

The crime spree prompted a San Fernando Valley-wide tactical alert, with hundreds of LAPD officers on the lookout for the suspect and a dark-blue SUV they say he was driving.

LAPD helicopters blanketed the Valley, with several flying low over areas where police believed Zaragoza had been.

Not long before he was caught, police and witnesses said Zaragoza boarded an Orange Line bus in Lake Balboa, then, at around 1:30 p.m., pulled out a gun and shot a passenger in the head near Victory Boulevard and Woodley Avenue.

When Zaragoza appeared in Canoga Park for the third time Thursday, police said, two officers in plain clothes saw and arrested him.

He was armed with a similar-caliber weapon used in the homicides, police said, but it hadn’t been confirmed yet whether that was the same weapon.

“Plain-clothes officers that had been surveilling the area … took him into custody,” said Capt. Billy Hayes, who leads the LAPD’s robbery-homicide division. “There was a small use of force but he was taken into custody. It is obviously an individual who went on a violent spree. … We put tremendous assets on this.”

“We don’t know exactly what the motive was or why (the victims) were targeted,” said Lt. Kirk Kelley of the North Hollywood shooting.

Hayes said police were seeking to interview the suspect’s mom to try and learn what led up to the violence: “We’re going to be trying to talk to her.”

Hours after the first shooting, in the 21900 block of Roscoe Boulevard, police tape fluttered just outside the entrance to the apartment building. An LAPD officer in tactical gear and sunglasses, with a large rifle slung across his chest, stood out front on a tidy patch of grass and trees. Detectives in suits could be seen milling around a corridor from the parking alley to the apartment building’s interior.

The three victims had been found inside a bloody, first-floor unit.

Paramedics pronounced Zaragoza’s 20-year-old brother and 50-year-old father dead at the scene. The suspect’s mother was taken to a hospital.

Amanda Williams, 29, lives in an apartment building just east of the Canoga Park complex where the first shooting took place. Her balcony overlooks the alley where police vehicles and officers swarmed Thursday morning.

Williams woke up to the sounds of helicopters buzzing overheard, with police using their loudspeakers. She couldn’t hear what they were saying, but she sensed urgency.

“They were flying fast,” said Williams, who has lived in the neighborhood for nine years. “They were running – they were trying to find someone, you could tell.”

At around 10:30 a.m., family members arrived at the apartment and spoke to police. One appeared to be in tears. They soon left.

Ruth Barcenas lives in an apartment nearby. She often saw the victims: The mother would clean up the grassy area outside, waving to her neighbors as they walked by. The father would often go out for a smoke. But she said she’s never seen the suspect.

“They were a really good couple, nice people,” Barcenas said.

The second shooting broke out at about 2:45 a.m. at a gas station on the 6700 block of Vineland Avenue in North Hollywood.

“We’re still trying to figure out how he made his way there,” said LAPD spokesman Josh Rubenstein. “But there was a very short time in between (the shootings).”

Rubenstein said police believe Zaragoza shot the two victims, a man and a woman, outside the gas station. She died at a hospital. The man remained in critical condition Thursday. Police have not disclosed the relationship between Zaragoza and these victims.

Hours later, detectives surrounded what appeared to be a trail of blood outside the Shell gas station and food mart. Several bullet holes could be seen in the wall of the building.

Police said the attempted robbery was at 7:45 a.m., outside a bank of America in Canoga Park at Sherman Way and Topanga Canyon Boulevard.

No one was hurt.

“The guy at the bank was lucky,” Capt. Hayes said.

At around 1:30 p.m., police learned of another Valley shooting – this time on the dedicated bus lane for the Orange Line as it passes through Lake Balboa.

Los Angeles police responded in force, setting up a perimeter. Officers were stationed at intersections with orders to search every vehicle exiting the area.

On the bus, two passengers said, the suspect would make people move out of his way when he moved about. At one point, they said, he pulled out a handgun and, unprovoked, shot another passenger.

“He was acting weird, he was trying to press on people,” said one of those passengers, Carlos Hurtado, 23. “He was trying to make people know he was a bad guy.”

Said the second of these passengers, Luis Rodriguez, 41: “It could have been anybody. I could have sat where (the victim) was sitting. It’s like he was going, ‘”Eeny, meeny, miny, mo.’ “

The bus stopped, and the suspect got off and melded into the city.

An hour later, back in Canoga Park, at a window shop near Canoga Avenue and Gault Street, officers in plain clothes, perhaps tipped off, spotted the suspect. They used a stun gun on the suspect, then arrested him, Sgt. Timothy Kohl of the LAPD said.

It was unclear where the suspect’s SUV had ended up.

Carlo Bagdasarian, 52 was working at an auto-repair shop in the area. He saw a man filming with a cellphone right outside the shop’s garage and went for a look.

When he turned a corner, Bagdasarian said, he saw at least 15 police officers, mostly in plain clothes and bulletproof vests, pressing a suspect up against the glass window of a business.

He recognized the suspect as Zaragoza, he said, because the suspect’s photo had been broadcast on television throughout the day.

Staff writers Richard K. De Atley and Elizabeth Chou contributed to this report.