A transgender woman accused of trying to light a flag on fire in a crowd at Philadelphia's Pride parade Sunday was sent to a men's prison before activists and others — including the city's LGBT affairs director — helped bail her out.

The District Attorney's Office announced Wednesday it had dropped some of the charges against the suspect, ReeAnna Segin, but the incident has still sparked concerns about where authorities house transgender suspects.

Here is what we know:

How do Philadelphia police decide what gender to classify a person?

Police use the gender listed on the suspect's government-issued identification card, unless the person has had gender-reassignment surgery.

Surgery, however, isn't required to identify as transgender, which means identifying with a gender different from the one with which a person was born. As the national LGBT organization GLAAD notes, not all transgender people can afford surgery.

The police department does require officers to refer to transgender suspects by their preferred name and pronoun. (Police publicly identified Segin as female but used her birth name, Ryan Segin, because that was the only name she provided, the department said Tuesday.)

What happened after police arrested Segin?

Segin was placed in a single-occupancy cell at Philadelphia police headquarters — the department's policy is to hold transgender arrestees in single-cell occupancy "whenever practical" — before officers transported her to the Curran-Fromhold Correctional Facility. The facility houses men and is run by the Philadelphia Department of Prisons.

Officers arrest Segin.
BASTIAN SLABBER / For the Inquirer
Officers arrest Segin.

The prisons, a spokeswoman said, follow similar guidelines to the police: Inmates are generally housed in a facility matching the gender listed on their ID, unless they have had gender-reassignment surgery. The spokeswoman, Shawn Hawes, said the prisons also work with medical and behavioral health service providers to determine the best placement.

Segin's bail was set at $5,000, and 10 percent — or $500 — had to be posted for her to be released, Hawes said.

Amber Hikes, the city's LGBT affairs director, said Monday afternoon on Facebook she had helped post Segin's bail.

For the sake of transparency: Yesterday at the beginning of the Pride parade, a trans woman was arrested at 12th and…

Posted by Amber Hikes on Monday, June 11, 2018

Why is it important for transgender inmates to be housed in the right space?

Transgender individuals face a high risk of assault while incarcerated. Nearly 30 percent of transgender individuals — or 166 of 554 — held in jails, prisons or juvenile detention centers reported that staff or other inmates had physically or sexually assaulted them in the past year in a 2015 survey by the National Center for Transgender Equality.

Just this week, the American Medical Association urged that transgender prisoners be placed in correctional facilities that reflect their affirmed gender status. The association cited the violence that transgender inmates face when they are housed in facilities according to their biological sex.

Is anything being done to change how transgender inmates are housed in Philadelphia?

Hikes said on Facebook her office was trying to make changes.

Facebook screenshot

But Hikes also said the issue is complicated: Transgender men don't always feel comfortable or safe being housed with cisgender men (cisgender means people who identify with the same gender they were born with), and not all transgender women feel safe with cisgender women.

Facebook screenshot

What else do we know about the incident that led to Segin’s arrest?

Segin, who is from Woodbine, N.J., was arrested around 12:10 p.m. Sunday at 12th and Locust Streets, where crowds had assembled for the annual Pride parade, authorities said.

While flag burning is not illegal, police said Segin tried to set the blaze amid a crowd. She was charged with attempt to commit arson, risking a catastrophe, recklessly endangering another person, and possessing an instrument of crime.

The District Attorney's Office on Wednesday dropped the arson and catastrophe charges — both felonies — but said Segin still faces the remaining charges, which are misdemeanors. Officers found road flares protruding from Segin's backpack, which also contained a can of paint thinner and a blue lighter stick, authorities said.

Police described the flag she allegedly tried to burn as "a thin blue line American flag." It had black and white stripes along with a blue stripe. Some people on social media referred to it as a Blue Lives Matter flag, though it's unclear whether that was the case.

Blue Lives Matter, a movement to honor police officers, was created in response to Black Lives Matter, a movement that has called out police killings of people of color.

Police hold the flag.
BASTIAN SLABBER / For the Inquirer
Police hold the flag.