A parole officer's tip paved the way for the arrest of one of two main suspects in the Dodger Stadium parking-lot beating of a San Francisco Giants fan, the Los Angeles police chief said in a Sunday press conference at the stadium where the incident occurred.

The Associated Press reported that police chief Charlie Beck confirmed Sunday that one of the two men suspected of attacking Giants fan Bryan Stow on Opening Day was taken into custody early Sunday and charged with assault with a deadly weapon. Giovanni Ramirez, 31, was being held on $1 million bail, police said in a statement.

As the Los Angeles Times reported, the LAPD's SWAT team descended on an East Hollywood apartment building with guns drawn and a warrant in hand around 7 a.m. PT.

Among those removed from the targeted apartment was a man with a bald head and tattoos on his neck and arms -- matching the sketches released by police in the weeks after Stow's beating.

Stow, a 42-year-old paramedic and father of two, remains in critical condition since suffering brain damage, but has since been moved from the Los Angeles County-University of Southern California Medical Center to San Francisco General Hospital.

Beck said the suspect is believed to be the "main aggressor" in the beating. Beck lauded the 20 detectives who have worked the case, going after 630 leads. The apprehended suspect had been detained for interrogation following the use of a police search warrant.

Beck became emotional when describing the call he received Sunday morning from Assistant Chief Earl Paysinger, according to the AP.

"He said the words I've been waiting for for seven weeks. He said that we had Bryan's assault suspect in custody," Beck said. "This is a huge step."

The AP also reported that LAPD Sgt. Kunch said it was unclear if the other detainees from the scene were potential suspects or witnesses in the beating, which occurred after the March 31 game between the Dodgers and Giants.

Stow was walking through the Dodger Stadium parking lot with friends when he was brutally attacked. Reportedly, the two assailants repeatedly kicked and punched Stow -- who was clad in Giants gear -- while he was on the ground, before fleeing the scene.

This week, police announced they were also looking to identify a woman who helped the attackers escape by driving them away. The driver was described as a Latina woman in her 20s, standing about 5-foot-2. She had brown or dyed hair worn in a ponytail, and was wearing a white Andre Ethier jersey. She was reportedly driving a white four-door sedan with a boy, about 10 years old, in the vehicle.

Police have said a reward of $200,000 would be offered for information leading to the arrest of the two assailants, who were reportedly wearing Dodgers gear.

According to the AP, Stow's sister, Bonnie, told a Los Angeles television station that police called her family on Sunday to let them know about the search warrants.

"I can't even tell you the emotions that we're going through right now," a teary-eyed Bonnie Stow told KABC-TV, the AP reported. "To be excited is the least we can say."

Also, San Francisco mayor Ed Lee said he called Los Angeles mayor Antonio Villaraigosa to thank him personally and congratulate him on the breakthrough in the case.

"That sort of brutality is totally unacceptable," Lee told the AP. "It's not only unacceptable, but needs to be dealt with. Our hearts are still open for a full recovery of Mr. Stow."

The Giants issued the following statement regarding the arrest:

"Today's arrest in the Bryan Stow case is welcome news in what has been a very difficult time for the Stow family. We commend the Los Angeles Police Department for their hard work and we are confident that they will continue to dedicate themselves until all of those responsible for this senseless act of violence have been brought to justice. Our thoughts and prayers remain with Bryan Stow and his family and we thank the community for its tremendous support for the Stow family during this difficult time."

Giants manager Bruce Bochy, who learned of the arrest on Sunday morning, said: "Great news. I know it's been hard on the family, but for them to continue to work as hard as they have been -- I'm talking about the police department -- and have a suspect in hand, it's great news. Hopefully they'll catch everyone who was involved in this senseless act."

The San Francisco Chronicle reported this week that Stow's doctors "expressed a measure of optimism" after his seizures had been controlled and he had begun to spontaneously open his eyes.

On Sunday, Dodgers owner Frank McCourt also echoed the sentiments of gratitude in a statement released by the club.

"First and foremost, our thoughts today are with Bryan Stow and his family and we hope that this announcement brings them a small measure of relief in what has been an extremely difficult time in their lives," McCourt's statement read.

"On behalf of the Dodger organization and our fans, I want to extend our most sincere appreciation and 'thank you' to Chief Charlie Beck and the men and women of the Los Angeles Police Department. From the outset, the Chief made an unwavering commitment to do everything possible to find and apprehend the suspects in the brutal and cowardly attack that took place against Mr. Stow on Opening Day.

"From that point forward, I gave my word to Chief Beck that he would have the full support of everyone at the Dodgers and we have worked in close partnership with the LAPD on this matter. We pledge our continued cooperation with law enforcement authorities during the prosecution phase that will ensue. 

"The Dodgers are committed to providing our fans the safest sports venue in the United States -- this is a commitment that we take very seriously.

"Chief Beck, thank you for using every available LAPD resource to find and arrest this suspect, who will now be brought to justice."