Update2: San Diego Sheriff Bill Gore confirmed John Earnest as the suspect.

Update #7 @SDSheriff Bill Gore confirms the name of the shooting suspect as 19-year-old John Earnest (DOB 6/8/99). We didn't find any prior law enforcement contact with Earnest. We're looking into digital evidence and checking the authenticity of an online manifesto. — San Diego Sheriff (@SDSheriff) April 28, 2019

Update: The shooter has been confirmed as 19-year-old John T. Earnest.

Multiple Law Enforcement Sources Familiar w/the Investigation Tell NBC News that the Shooter (Synagogue in Poway, CA) is John T. Earnest (DOB: 6/8/99 - 19 yrs old) — Esmeralda Medellin (@esmeraldamedel6) April 27, 2019

NBC San Diego reports that "an off-duty U.S. Border Patrol agent who was in the synagogue at the time of the shooting opened fire on the suspect, missing the man but striking his vehicle."

ARMED off duty law enforcement stopped the San Diego synagogue killer and saved many lives.



This is why every America should have the ability to arm themselves whenever they choose. — John Cardillo (@johncardillo) April 27, 2019

President Trump - who the synagogue shooter allegedly disavowed as a "Zionist" - called the shooting a hate crime and offered his "deepest sympathies."

President Trump calls the shooting at a synagogue in Poway, California, a “hate crime” and “hard to believe." He adds, "My deepest sympathies to all of those affected." https://t.co/XVORtke1Bi pic.twitter.com/sAjHV2o73q — CNN (@CNN) April 27, 2019

Meanwhile, governor Gavin Newsom said in a tweet "Hate continues to fuel horrific and cowardice acts of violence across our state, country and world. It must be called out. CA stands with Poway."

Charleston, Pittsburgh, Quebec, New Zealand — now our own Poway, California.



No one should ever fear going to their place of worship.



Hate continues to fuel horrific and cowardly acts of violence across our state, country, and world. It must be called out. CA stands with Poway. — Gavin Newsom (@GavinNewsom) April 27, 2019

As reported earlier, Earnest appears to have posted an "open letter" manifesto as well as a message on 8chan prior to the attack. See below for details.

***

One woman is dead and at least 3 other people have been injured after a gunman opened fire on a Poway, California synagogue on Saturday just before 11:30 a.m. on the last day of Passover.

The mayor of the northern San Diego suburb, Steve Vaus, confirmed the death to NBC 7 just after 1:30 p.m.

The suspect - a 19-year-old man, was detained down the road from the synagogue, according to San Diego County Sheriff's Department Sgt. Aaron Meleen.

Update #5 @SDSheriff Bill Gore confirms one person was killed and three others were injured in the #synagogueshooting at Chabad of Poway. Our hearts go out to those affected by this incident.

19-year-old man was arrested in connection with the shooting by @SanDiegoPD. — San Diego Sheriff (@SDSheriff) April 27, 2019

The Chabad synagogue serves as a community center for ultra-Orthodox Jews, according to NBC News.

Chabad is an Orthodox Jewish Hasidic movement. The shooting coincides with the end of Passover. https://t.co/YYJDcr2G7W — Joyce Alene (@JoyceWhiteVance) April 27, 2019

According to local Steve Werby, who spoke with a Deputy Sheriff, has been monitoring the police radio bands, and whose wife was on scene, said that two children were injured, while two others are missing.

Shooting inside the Chabad of Poway, California. Just across city of San Diego border. During religious services. At least one person shot. 2 children injured. 2 children missing. My source is deputy sheriff via direct conversation, police band, and relative of person at Chabad. https://t.co/21RRgaJVmo — Steve Werby (@stevewerby) April 27, 2019

Werby also said that police were preparing to enter the home of the suspect, who lives with his parents - and that Rabbi Yisroel Goldstein lost two fingers in the attack.

All 4 victims of the Chabad of Poway shooting are now at Palomar Medical Center. Victims of the shooting at the synogogue include Rabbi Yisroel Goldstein who lost 2 fingers, another adult I know, and 2 minors. One minor age 11. #sandiego #poway #chabad #activeshooter #hatecrime https://t.co/FuCnODj8RK — Steve Werby (@stevewerby) April 27, 2019

He also tweeted: "According to an adult inside the synogogue during the shooting at Chabad of Poway synogogue, there were 6 or 7 shots, screams, then 6 or 7 more shots. Source is my wife who is talking to the adult."

According to an adult inside the synogogue during the shooting at Chabad of Poway synogogue, there were 6 or 7 shots, screams, then 6 or 7 more shots. Source is my wife who is talking to the adult. #sandiego #poway #chabad #hatecrime https://t.co/6RRUn3dK3C — Steve Werby (@stevewerby) April 27, 2019

While currently unconfirmed - internet sleuths have tenatively identified the suspect a 19-year-old local John Earnest - who appears to have posted about the attack on the 8chan prior to the incident.

John Earnest's manifesto has the writer DESCRIBE themselves as a 19 year old male.

Police just said the suspect is 19 years old.



It's him.



Police need to speed the hell up pic.twitter.com/VFmDyYbhAs — Nick Monroe (@nickmon1112) April 27, 2019

There is also an "open letter" manifesto in which Earnest explains that he is a "man of European ancestry," who says he also "scorched a mosque in Escondido a week after Brenton Tarrant's sacrifice," referring to last month's New Zealand Mosque shooter which the manifesto says was the "catalyst for mer personally."

Of note, there was an early morning arson at a nearby Mosque in Escondido, California on March 24th which remains unsolved. While several people were sleeping inside, one person who was awake spotted the flames and managed to put out the fire.

Members of Escondido’s Muslim community talk about the apparent arson attack. (OnSceneTV)

The potential suspect's "manifesto" also has a series of Q&As in which he says he is not a Trump supporter.

“Are you a Trump supporter?” You mean that Zionist, Jew-loving, anti-White, traitorous cocksucker? Don’t make me laugh. -Manifesto

The time stamp seems to match the manifesto..... https://t.co/yyyaO0Ii1E — Mike Cernovich (@Cernovich) April 27, 2019

Here is the potential suspect's 8chan post. Again, this is unconfirmed as of this writing.

Here's the 4Chan post he posted about it, similar to the Christchurch shooter that posted his manifesto on 8Chan pic.twitter.com/LSe5cUDTnS — Sean Bekkers (@WarDogCS) April 27, 2019

The "Manifesto" reads:

To my brothers in blood. Make sure that my sacrifice was not in vain. Spread this letter, make memes, shitpost, FIGHT BACK, REMEMBER ROBERT BOWERS, REMEMBER BRENTON TARRANT, filter the religious D&C, and filter the schizos who will inevitably call this a ‘false flag.’ Something to note, people grossly overestimate the police’s ability to solve ‘crimes’ such as ‘arson’ and ‘murder.’ Lots of threads about ‘Feds are talking to me guys because I post on 8chan, it’s so spooky’ are ‘organically’ popping up. What a load of shit meant to try to scare the goyim and prevent retaliation.

The author of the note claims to be a "a 19 year old nursing student from the depths of Commiefornia."

For more live developments, follow journalist Nick Monroe's thread by clicking on the tweet below:

"At least 4 people (including 2 children) shot during a #Passover holiday celebration at Chabad Poway synagogue in San Diego." pic.twitter.com/NP3b7gteZU — Nick Monroe (@nickmon1112) April 27, 2019

Act quickly though - it appears Twitter is hard at work censoring Nick's information: