(CNN)French police and security forces killed three terror suspects on Friday in two simultaneous gunbattles, authorities said.
Charlie Hebdo attack: What we know and don't know
The two suspects in the deadly attack on Charlie Hebdo magazine died after police surrounded a print shop where they were holed up in a town outside Paris.
At the same time, police stormed a kosher grocery store in eastern Paris and killed a man suspected of killing a police officer on Thursday. Four hostages inside the store died. A fourth suspect is at large.
Here's a summary of what we know and don't know:
THE LATEST -- PARIS
What we know: A hostage situation at a kosher grocery store in Porte de Vincennes, a neighborhood in eastern Paris, ended about 5 p.m. local time (11 a.m. ET) after police stormed the establishment. Four hostages and the hostage-taker were killed, authorities said.
Amedy Coulibaly, who took the hostages and was a suspect in the slaying of the police officer in Montrouge, was killed, Alliance Police Union spokesman Pascal Disant said. Police had been looking for Coulibaby and the woman he lived with, Hayat Boumeddiene, 26, who also is a suspect in the police officer's death.
Disant said Boumeddiene may have been in the supermarket but was not captured by police. The interior ministry has not confirmed that she was inside the store. Her whereabouts are unknown and police are searching for her.
Four hostages were killed and 15 survived, according to Israeli government sources who characterized a phone conversation between Israeli Prime Minister Benjamin Netanyahu and French President François Hollande.
Hollande called the incident an "anti-Semitic attack."
Disant said at least 10 hostages managed to escape. Some police officers were injured.
A man claiming to be Coulibaly told CNN affiliate BFMTV that he belonged to the Islamist militant group ISIS. CNN cannot independently confirm the authenticity of the recording.
What we don't know: Where is Boumeddiene? Was she really inside the grocery? Exactly how many hostages escaped?
THE LATEST -- DAMMARTIN-EN-GOELE
What we know: Security forces killed Charlie Hebdo attack suspects Said and Cherif Kouachi outside a print shop in an industrial part of Dammartin-en-Goele, a town about 25 miles northeast of central Paris, according to district Mayor Bernard Corneille. A man inside the building, initially described as a hostage, is safe, he said.
The Kouachi brothers came out of a shop where they'd holed up and opened fire on police forces, BFMTV said. The station reported that a man initially described as a hostage was hiding in the building and that the brothers were unaware of his presence.
Automatic weapons fire and at least three large explosions could be heard from the scene about 5 p.m. (11 a.m. ET.) A helicopter landed next to the building and live footage from BFMTV showed men on the roof of the building where the brothers were believed to be.
Lawmaker Yves Albarello -- the local member of Parliament for the district where the police operation took place -- said the suspects spoke to police by phone and said they wanted to die as martyrs.
What we don't know: Police have not confirmed whether they moved in after the suspects started firing. Nor have they confirmed whether the man rescued safely was a hostage. It's not known why the attackers chose to enter this town in the first place.
THE CHARLIE HEBDO ATTACK
What we know: About 11:30 a.m. (5:30 a.m. ET) Wednesday, a car pulled up outside the Charlie Hebdo office in Paris' 11th district. Two people got out. They were dressed in black, carried what appeared to be automatic weapons and had their faces covered.
The gunmen asked maintenance men where the magazine office was and opened fire, killing one of the workers.
They made their way to the office on the second floor and headed to the newsroom, opening fire again, killing 10 people this time. The staff of the magazine, which is published each Wednesday, was in a lunchtime editorial meeting when the gunmen burst in. Hebdo's editor and a police officer who was in charge of protecting him were among those killed.
The gunmen asked for specific people by name before killing them, said a doctor who helped the injured. Dr. Gerald Kierzek said the gunmen divided the men from the women before opening fire. The shooting was not a random spray of bullets, he said, but more of a precision execution.
The gunmen left the building and drove off with a third suspect, encountering and exchanging fire with police three times. A second police officer was shot and killed in the final exchange.
What we don't know: Investigators are still working on what happened inside the office of Charlie Hebdo.
The attack appeared highly organized, down to a detailed getaway plan. It's not yet clear if the gunmen had help.
"Several detentions" took place overnight in connection with the shootings, Prime Minister Manuel Valls said Thursday, without specifying how many.
What we know: The two brothers accused of carrying out the Charlie Hebdo attack, Cherif Kouachi and Said Kouachi, are dead. So is grocery store suspect Amedy Coulibaly, authorities said.
Those three men were part of the same same jihadist groups, Disant said. Paris prosecutor Francois Molins said Cherif Kouachi's wife and the girlfriend of Amedy Coulibaly, Boumedienne, exchanged 500 phone calls in 2014. Furthermore, the wife told investigators that her husband and Coulibaly knew each other very well.
The Prime Minister said Thursday that the suspects were "known to the security services." Both brothers were in the U.S. database of known or suspected international terrorists, known as TIDE, and also had been on the "no-fly" list for years, a U.S. law enforcement official said.
Cherif Kouachi, 32, was convicted in 2008 of being part of a jihadist recruitment ring in Paris that sent fighters to the war in Iraq.
A French source close to the French security services said that investigators are looking at evidence to suggest that Cherif went to Syria, and that he returned from this trip -- of unknown length -- to France in August 2014. USA Today reported that both brothers returned from Syria in the summer.
Less is publicly known about Said Kouachi, 34. But CNN affiliate BFMTV reported that his ID card was discovered during the investigation into the attack, helping police single out the suspects.
According to U.S. officials, Said spent several months in mid-2011 in Yemen receiving weapons training and working with al Qaeda's affiliate there, al Qaeda in the Arabian Peninsula (AQAP). This would place him in Yemen during the time that senior figure Anwar al-Awlaki was still alive.
Al-Awlaki was killed in September 2011 in a U.S. drone strike. While it's not absolutely definitive, the United States believes it's likely and possible that Said Kouachi and Awlaki crossed paths, but it's not known if they would have met for any extended period of time.
A third suspect in the Charlie Hebdo attack, Hamyd Mourad, 18, turned himself in to police Wednesday, a source close to the case told the news agency Agence France-Presse. But French media outlets reported his release Saturday. Reports in French media and on social platforms suggested he was at school in northeastern France at the time of the attack.
Some experts warned that how well the gunmen in the attack wielded their weapons, hid their identities and apparently planned their escape showed a marked difference form other "lone wolf" attacks.
Writing for CNN, retired Lt. Gen. Mark Hertling, former commander of U.S. Army Europe, wrote that the gunmen appeared well-trained.
As for Coulibaly, a Western intelligence source told CNN that he went by the alias Doly Gringny. The source said he was a close associate of Cherif Kouachi. The two were involved in a 2010 attempt to free an Algerian serving time for the 1995 subway bombing, the source said.
Coulibaly was arrested in May 2010 with 240 rounds of ammunition for a Kalashnikov rifle. He also had a photo of himself with Djamel Beghal, a French-Algerian once known as al Qaeda's premiere European recruiter, who was convicted of conspiring to attack the U.S. Embassy in Paris.
Coulibaly was indicted in the prison break plot, but there was not enough evidence to charge Cherif Kouachi, the source said. Cherif Kouachi visited Coulibaly during pre-trial detention.
Coulibaly lived with Boumeddiene, the source said. The two traveled to Malaysia together.
A man claiming to be Amedy Coulibaly told CNN affiliate BFMTV on Friday that he belonged to the Islamist militant group ISIS.
What we don't know: Were the suspects working with anyone else? And were their attacks directed by terrorist networks? The FBI and U.S. intelligence agencies are mapping their relationships for clues, including digital records. They are also running the suspects' names through databases and looking for connections with ISIS and al Qaeda.
An ISIS radio broadcast Thursday praised the attackers, calling them "brave jihadists." But the broadcast did not say whether the two had any connection to the militant group.
THE VICTIMS IN THE CHARLIE HEBDO ATTACK
What we know: At least 12 people were killed in the attack, including police officers and some of the most revered and controversial cartoonists in France.
Charlie Hebdo editor Stephane "Charb" Charbonnier was among the dead.
At least seven other journalists were killed, including well-known cartoonists Georges Wolinski, who worked under the pen name Wolinski, Jean "Cabu" Cabut, Bernard "Tignous" Verlhac and Philippe Honore, known as Honore.
Also killed was journalist, economist and Charlie Hebdo shareholder Bernard Maris, BFMTV reported.
A maintenance man and two police officers also died, according to authorities.
The two police officers killed were identified as Ahmed Merabet and Franck Brinsolaro.
Eleven people were wounded in the attack, including four in serious condition.
What we don't know: All the victims have been identified, but over time, more stories of these lives cut tragically short by terrorism are likely to emerge.
What we know: During the Charlie Hebdo attack, the gunmen said, "Allahu akbar" -- which translates to "God is great" -- and that they were avenging the Prophet Mohammed, the prosecutor told reporters.
Charlie Hebdo has a controversial history of depicting Mohammed, often in an unfavorable light, which has angered many Muslims around the world. Earlier cartoons depicting Mohammed spurred protests and the burning of the magazine's office three years ago.
Its last tweet before Wednesday's attack featured a cartoon of ISIS leader Abu Bakr al-Baghdadi offering festive greetings with the words, "And, above all, health!"
President Francois Hollande described the kosher grocery story attack as an "anti-Semitic" act.
What we don't know: Was the Charlie Hebdo attack part of a coordinated strategy? Was Coulibaly working with the Kouachi brothers or did he simply respond to their attack by launching his own? Were his attacks opportunistic or planned in advance?