Ahmed Abu al-Homs's life changed forever as the 13-year-old was on his way to see his sister and became caught up in clashes between Palestinians and Israeli police.
He was hit by an Israeli anti-riot bullet during the January clash in east Jerusalem, leaving the young Palestinian in a coma for 45 days. When he came out of it, a piece of his skull was gone.
"Before, Ahmed was an intelligent boy, lively and dynamic," his uncle Mehdi al-Homs said of the teenager, whose head still bears scars and stitches.
"Now all he can do is walk, and not for very long. He has difficulty expressing himself and remembering things."
Homs is among the Palestinians wounded by a new type of anti-riot bullet Israeli police began using around two years ago, rights groups say.
While not designed to be lethal, the bullet's ability to inflict heavy damage has raised concern. Israeli police regularly use such sponge-tipped bullets during clashes in mainly Palestinian east Jerusalem.
In January 2015, police were given the authorisation to use what is known as bullet model 4557 in east Jerusalem, said Nesrine Aliane, a lawyer with the Association for Civil Rights in Israel.
Capsule-like in shape, the bullets have a hard plastic base and a rounded tip covered in hard black foam.
Some six centimetres long and three centimetres wide, they are heavier than the previous model used, ACRI says.
While official authorisation did not come until January 2015, police had in fact been using them since July 2014 as violence escalated and eventually led to that year's conflict in the Gaza Strip, said Aliane.
More than 30 Palestinians in east Jerusalem have been wounded since police began using them, most with head injuries, she said.
Aliane said 14 have lost an eye.
As for Homs, he can no longer read or write and spends most of his time in his family's home in the Issawiya neighbourhood of east Jerusalem.
- Irresponsible use? -
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In September 2014, 16-year-old Mohammed Sonoqrot died from his wounds after being hit by one of the bullets on August 31.
"He is dead because he was hit with a bullet in the head fired from very close range," Aliane said.
ACRI says Israeli police closed the case in May without charging anyone, citing a lack of evidence.
Rights groups say that while they are supposed to be non-lethal, there are risks related to how the bullets are used.
Fired at the legs from at least 10 metres away, the bullets cause severe pain, but are not supposed to leave permanent damage.
"The problem is that they are being used in ways that are irresponsible," said Sari Bashi of Human Rights Watch.
"What we see in east Jerusalem is that police are using an excess of force -- unnecessary force against demonstrators -- and they are failing to take precautions to protect civilian demonstrators, especially children."
Israeli police spokeswoman Luba Samri said officers have a duty to protect residents from the danger of rock-throwing and the hurling of Molotov cocktails.
She stressed that those actions by protesters can kill.
Samri said police always acted "in compliance with the law and principles of self-defence."
When using weapons designed to be non-lethal such as the sponge-tipped bullets, it is done "reasonably, with moderation" and while seeking to cause the least damage possible, she said.
However, Nafez al-Damiri, 55, paid dearly for finding himself at the wrong place at the wrong time in July 2015, as clashes broke out at east Jerusalem's Shuafat refugee camp, where he lives.
The deaf man was frightened and sought shelter in a grocery store. Surveillance video shows him being hit in the face with an anti-riot bullet, leaving him with fractures and a glass eye.
He had previously worked as a tailor, but he no longer leaves home. His wife Ghada said she has also had to give up her work as a house cleaner to take care of her husband.