Report: 14-year-old boy to be charged with murdering 73-year-old man. Victim was chased by gang of teens, beaten with traffic cone.

UPDATE: The 14-year-old boy has been charged with murder, WCAU-TV reported, citing Philadelphia police.

Original story below

A 14-year-old boy is being processed on charges of third-degree murder and conspiracy in connection with the brutal beating of 73-year-old James Lambert in north Philadelphia late last month, KYW-TV reported, citing sources close to the investigation.

Teenagers were caught on video beating Lambert with a traffic cone on a street just after 2:30 a.m. June 24; he died the following day, WCAU-TV reported.

Image source: WCAU-TV video screenshot, composite

What are the details?

The 14-year-old boy and and his 10-year-old brother surrendered to authorities around 4 p.m Monday, KYW reported. Sources told the station that the 10-year-old brother has since been released.

Image source: KYW-TV video screenshot

Police added to KYW that the brothers were among seven juveniles — four males and three females — seen on security video of the deadly attack on Lambert along the 2100 block of Cecil B. Moore Avenue.

When KYW asked District Attorney Larry Krasner if he expects to charge any of the teens with murder, he replied, “Certainly on the very limited information we have, it seems very likely, yes."

Philadelphia District Attorney Larry KrasnerImage source: KYW-TV video screenshot

Elsie Stephens, the victim’s grieving sister, told the perpetrators to "turn yourself in. How could you let us suffer like this? You took him away from us."

Elsie StephensImage source: KYW-TV video screenshot

Officials told KYW they've been in contact with some, but not all, of those seen assaulting Lambert, and police added that they expect others in the video to turn themselves in as well.

What happened during and after the attack?

The first attacker is seen in the clip striking Lambert — who's blurred in the video — with a traffic cone as the victim tries to cross the street and get away from the group.

Image source: WCAU-TV video screenshot

After Lambert lands on the sidewalk, another teen appears to use a cellphone to take a photo or video of Lambert.

Image source: WCAU-TV video screenshot

A third teen is seen picking up the same traffic cone and throwing it at the victim.

Image source: WCAU-TV video screenshot

"The teens struck the victim several times with objects, knocking the victim to the ground causing injuries to his head," police said in a news blotter. "The victim was transported to the hospital where he died of his injuries the following day."

The video also shows the suspects leaving the scene — and two of them appear to be smiling:

Image source: Philadelphia police

The teens apparently gathered after the attack, and one was seen acting out what appeared to be a "stumbling person," the station said.

Police said they hope video of the attack — and a $20,000 reward — will help locate those responsible, WCAU reported.

If you spot the teens from the video or accompanying images, the station said to call 911 immediately. Those with information about the attack can submit anonymous tips by phone or text to 215-686-(8477) or online, WCAU said.

The following are additional images from the police department's video:

Image source: Philadelphia police

Image source: Philadelphia police

This story has been updated.