In 2006, members of the gang unit at the Camden County jail pulled some valuable evidence from the cell of a reputed leader of the Bloods.

Prosecutors say letters found in Tarell "Trigger" Ambrose's cell contained orders for a contract hit on a fellow member of the Bloods' G-Shine set, and threatened witnesses in a second gang-related shooting.

They say Ambrose ordered both shootings from jail, leading to the 2006 death of Lavonne Adkins, 19, of Willingboro, and the wounding of Maurice Brown, of Mount Laurel.

Ambrose faces trial this month in the Adkins shooting, and prosecutors plan to use those letters against him.

In the last several years, street gangs - particularly the Bloods - have been filtering down from Trenton and North Jersey, becoming an increasing presence in Camden County.

In that time, the jail's gang unit has become integral in keeping order in a crowded jail and providing intelligence to investigators on the street.

Since the unit was created in 2004, its members have originated or contributed to more than 100 criminal cases like Ambrose's. Two members of the unit are assigned to work with the Prosecutor's Office.

"They're a very useful group of people," said acting Camden County Prosecutor Joshua Ottenberg. "We can't just go knock on doors and say, 'We want to talk to you.' In jail, it's a different relationship."

At an annual awards banquet in May, the Prosecutor's Office honored the unit for its work.

The gang unit was established by Eric M. Taylor, who became the jail's warden in 2004, six years after retiring as chief of corrections in New York City, where he ran Rikers Island and 15 other facilities.

In New York, Taylor was a pioneer in recognizing the growing strength of gangs on the East Coast, and in realizing the role that jails could play in combating them.

When he arrived in Camden County, gangs weren't as prevalent as they are now. But since 2005, the unit has identified 850 gang members in the jail.

This week, gang members in the jail numbered 175.

"That's over 10 percent of your population," Taylor said.

Though the Bloods are the most prevalent, the jail also has members of the Crips, the Latin Kings and Nietas.

Jails and prisons are prime locations for gangs to recruit members and formulate their plans for the outside, making intelligence gathered from behind bars particularly valuable.

"They're more organized in the facility than they are on the streets," said Officer Wayne Norton, a member of the gang unit.

Gang members communicate with others on the outside through coded letters and phone calls. Inmates also pass messages through the windows to people on the street, using a strange system of hand signals.

It's not uncommon to see people sitting on the brick wall across Federal Street, waving their arms up like they're directing traffic and staring at the jail's slitted windows.

"After a while, you can understand it," said Sgt. Christopher Foschini, who runs the gang unit.

Foschini said the unit once intercepted a message from a Bloods member in another jail ordering the death of a Bloods member in the Camden County jail.

The message was to "put his head on a plate," Foschini said. The Camden County inmate was isolated for his protection.

The unit identifies gang members in a number of ways, often pegging them during intake interviews through jewelry, clothing, tattoos and branding. A "dog paw" brand is a Bloods identifier, as are red prayer beads.

Norton displayed a canvas tennis shoe taken from one inmate. Inked on one side of the shoe was the message "Men of Business." The letters MOB are signifiers for Member of Bloods, he said.

The shoe also read, "Dope Coke Weed Whatever, Man" and the Bloods creed "Death Before Dishonor."

Members of Nietas recently drew a large gang symbol on the floor of a cell and sealed it with several coats of floor wax.

Inmates sometimes admit their gang affiliation up front.

"They're proud of it," Foschini said.

"And they don't want to be housed with another gang," Norton added.

Inside the jail, gang members tend to "clique together," which is another giveaway for affiliation. Taylor said he doesn't try to segregate the gangs or split them up.

"I believe in a balance of power," he said.

Despite the increasing gang presence, and housing more than 1,600 inmates in a facility built for 1,267, Taylor said there's been remarkable little violence in the jail.

"That says a lot about the type of people who work here," he said.

Although the Bloods and other gangs stake lifetime claims on their members - the Bloods motto is "Blood in, Blood out" - Foschini talks to them, trying to discourage the gang life.

"They're supposed to be families," Foschini tells the gang members. "When your own family is ordering hits on you, is that something you want to be involved in?"

Contact staff writer Troy Graham at 856-779-3893 or tgraham@phillynews.com.