'A' (c. 1998-) is an Israeli Jew who, when he was a minor, was charged with acting as an accessory, to Amiram Ben-Uliel, in the Duma arson murders.
This article, dated 3 January 2016, seems to say that he is the same person as this un-named minor from the West Bank settlement of Tzufim, while this article suggests that he is Elisha Odess, whose father is the community rabbi in Tzufim, so it seems as if he actually is Elisha Odess - presumably the 'A' comes from the א (aleph) in אלישע (Elisha).
Discussing 'A', this article, dated 3 January 2016, says:
[Amiram] Ben-Uliel scouted Duma with the minor charged as an accessory, who allegedly participated in the planning of the attack.
This article, dated 3 January 2016, says:
For nearly two weeks most of the suspects refused to talk to investigators. Then Attorney General Yehuda Weinstein gave the Shin Bet a green light to use torture during the interrogations. ...
The use of torture, under the supervision of the courts, broke A., who apparently led investigators to Ben-Uliel. Ben-Uliel eventually confessed and reenacted the crime, presumably under similar pressure.
This article, dated 04 January 2016, says:
A Jewish extremist who had been suspected of involvement in an arson attack on Jerusalem’s Dormition Abbey was released from five months of imprisonment without charges Sunday night – after two other people confessed to the attack.
Mordechai Meyer, 18, of the West Bank settlement of Ma’aleh Adumim, was put under administrative detention in August. The Shin Bet security service ordered his jailing without charges immediately after a deadly firebombing by Jewish terrorists killed a Palestinian toddler and his parents in the West Bank village of Duma.
At a subsequent court hearing on his detention, the Shin Bet argued that Meyer was a danger to the public – not because it suspected him in the Duma attack, but because it had intelligence indicating he was involved in the attack on Dormition Abbey last February. Central District Court President Avraham Tal accepted this argument and approved Meyer’s detention twice.
But during the Shin Bet’s investigation of the Duma murders, two minors who were suspects in that case confessed that they, together with a third person, were responsible for the Dormition Abbey attack.
One minor, A., was charged on Sunday with involvement in both the Duma murders and the Dormition Abbey arson. The other, B., and the third person, Yinon Reuveni, were charged only with the Dormition Abbey attack. Unlike the minors, Reuveni hasn’t confessed.
This article, dated 15 July 2018, says:
State appealed against the release of the man, who was a minor during the incident, in which a 18-months-old and his parents were murderedEvents involving ‘A’ - Israeli Jewish minor charged as accessory in Duma arson-murder case:
The Supreme Court has ordered the release with restrictions of A., accused of involvement in the murder in the West Bank village of Duma, the attorney for the accused said on Sunday. The ruling was handed down after the State Prosecutor’s Office appealed the District Court’s decision to release A., who was a minor at the time of the alleged crime, and who has been jailed for more than two years.
The court said the minor must wear an electronic ankle monitor, remain under house arrest and deposit a bond of hundreds of thousands of shekels.
A., who was 17 when he was arrested, is accused of involvement in the murder of three members of the Dawabshe family in the firebombing of their home in July 2015. Eighteen-month-old Ali Dawabsheh was burned alive in the fire, while both his parents died from their injuries within weeks. He is not accused of murder because the prosecution could not prove that he was present in Duma on the night of the attack. He is also accused of involvement in the arson attack on the Dormition Church in Jerusalem and of other hate crimes.